VP2 rotation fix, NumBlok mini toggle, HW keyboard auto-hide, audit

ViewPager2 rotation phantom (Google Issue 175796502): - KeyboardView.onSizeChanged rebuilds buildPages() on any width transition including initial 0→actual layout, not just on resize. The first buildPages() from setup() runs at width=0 (view still detached), VP2's internal RecyclerView can't reliably re-anchor to the real dimensions that arrive later, leaving a fractional scroll offset that leaks the neighbor page on the right edge. A second buildPages() once the real size is known produces a clean result. - KeyboardView.lastModifierStates caches CTRL/ALT/SHIFT state so it survives the rebuild. - Works around an unfixed VP2 1.1.0 bug for non-FragmentStateAdapter usage. Fresh launches and all rotation paths confirmed clean on S23. NumBlok toggle on mini numpad: - KeyDefinition gains numLabel/numAction optional fields - KeyAction gains ToggleNumBlock data object - LayoutParser understands "numLabel"/"numAction" JSON and the "toggle_numblock" action type - KeyboardPageView.numBlockActive swaps label rendering; toggle key gets LOCKED-style amber glow while active - TerminalKeyboard.numBlockActive state; handleKeyAction swaps action→numAction; attachMiniTo carries state across rotation rebuilds - Mini last row: Num 0 \ (base) → Num Ins ~ (numblock) - Rows 1-3 map to PC-keypad nav: Home/↑/PgUp, ←/Esc/→, End/↓/PgDn - QuickBarCustomizer serializer/deserializer learned toggle_numblock Hardware keyboard auto-hide: - MainActivity derives hasHwKeyboard from LocalConfiguration.current. keyboard != KEYBOARD_NOKEYS && hardKeyboardHidden != HARDKEYBOARDHIDDEN_YES - LaunchedEffect(hasHwKeyboard) { ckbHidden = hasHwKeyboard } seeds the toggle on every HW kb connect/disconnect - In HW kb mode the kebab Show/Hide controls both CKB and QuickBar as a pair: val qbShownByUser = if (hasHwKeyboard) !ckbHidden else quickBarVisible - Normal mode unchanged (QB follows its own quickBarVisible pref) Number row dropdown: - KeyboardSettingsDialog now shows all four options (top/left/right/ hidden) in both orientations. Previously left/right were filtered out in portrait, preventing the user from setting the mini mode without first rotating into landscape. - Portrait-override on the effective numberRowMode stays in place (mini is landscape-only by design — documented in CLAUDE.md and auto-memory). Audit fixes: - KeyboardPageView: removed key.hint!! by capturing into a local hintText val so smart-cast flows through the render branches - SSHKeyLoader.loadEd25519FromPkcs8: require(seed.size == 32) so a malformed PKCS#8 blob fails fast with a clear message instead of crashing deep inside EdDSAPrivateKeySpec - vault_crypto.cpp nativeEncrypt: secure_zero(ptPtr, ptLen) before ReleaseByteArrayElements on all three paths (success + two error paths), matching the existing key-handling pattern for plaintext defence-in-depth through the JNI boundary Docs: - TECHNICAL.md: NumBlok, VP2 rebuild workaround, HW keyboard auto-hide, portrait mini override notes - CLAUDE.md: lib-terminal-keyboard module description updated with the same invariants - TODO.md: recently-completed items through 2026-04-06 - Audit.md: investigation log including false positives for future reference Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-04-06 13:23:13 +02:00 · 2026-04-06 13:23:13 +02:00 · e243b8e1e5
commit e243b8e1e5
parent f6f0e5e078
19 changed files with 278 additions and 56 deletions
--- a/Audit.md
+++ b/Audit.md
@ -0,0 +1,64 @@
+# Audit — 2026-04-06
+
+Comprehensive audit across all modules after the NumBlok / HW keyboard / VP2 rotation work in this session. Focus: security, bugs, dead code, file size, code quality. Debug infrastructure (TRACE logs, DevConfig receiver, SessionRecorder) is intentionally preserved and gated on the `dev` flavor.
+
+Parallel scan by module (lib-terminal-keyboard, lib-ssh, lib-terminal-view, lib-vault-crypto, app). Many reported findings were false positives on re-inspection — logged below for clarity.
+
+## Fixes applied
+
+### `lib-terminal-keyboard/src/main/kotlin/com/roundingmobile/keyboard/view/KeyboardPageView.kt`
+- **Removed `key.hint!!` on lines 201/208.** Captured `key.hint` into a local `hintText` val at the top of the render branches so Kotlin's smart-cast flows through the `if (hintText != null && hasBelowHint)` / `if (hintText != null && hasCornerHint)` checks. Drop-in safer replacement for the two `!!` assertions — no runtime behavior change.
+
+### `lib-ssh/src/main/java/com/roundingmobile/ssh/SSHKeyLoader.kt`
+- **Added `require(seed.size == 32)` in `loadEd25519FromPkcs8`.** A malformed PKCS#8 blob with a non-32-byte OCTET STRING would previously crash inside `EdDSAPrivateKeySpec(seed, …)` with a cryptic stack. Now it fails fast with a clear message: `"Ed25519 seed must be exactly 32 bytes, got $size"`.
+
+### `lib-vault-crypto/src/main/cpp/vault_crypto.cpp`
+- **Zero plaintext JNI buffer before `ReleaseByteArrayElements` in `nativeEncrypt`.** The existing code was already zeroing the key buffer (`secure_zero(keyPtr, keyLen)`) before release with `JNI_ABORT`, but leaking the plaintext buffer through the same path. Added three `secure_zero(ptPtr, ptLen)` calls — one on the normal success path, two on error paths (urandom failure, keyPtr acquisition failure). This matches the key-handling pattern and closes a defence-in-depth gap for sensitive plaintext passing through encrypt. On Android ART, `GetByteArrayElements` returns a JVM-managed copy, so zeroing does not affect the caller's input array.
+
+## Findings that were NOT real issues (documented to avoid re-flagging)
+
+### `lib-terminal-keyboard/TerminalKeyboard.kt`
+- "Comment syntax error `/ NumBlock…` on lines 173/814" — **false positive**. Both lines use valid `//` comments; the agent misread the indentation.
+- "`_rawJson!!` on line 1086" — **false positive**. Guarded by the enclosing `if (kl == null && _rawJson != null)` check; `!!` is safe.
+- "Race condition on `numBlockActive` between UI and touch threads" — **false positive**. Both `handleKeyAction` (toggle) and `KeyboardPageView` rendering (read) run on the main thread.
+
+### `lib-terminal-keyboard/KeyboardView.kt`
+- "Rapid rebuilds via `onSizeChanged` could lose state" — **not a real issue**. The rebuild is idempotent: it re-creates the ViewPager2 and re-applies cached `lastModifierStates`. Debouncing would hide legitimate resize events.
+
+### `lib-terminal-keyboard/QuickBarView.kt`
+- "`VelocityTracker.recycle()` on line 747 is unreachable after return" — **false positive**. The recycles on 731 and 747 are in two separate `if`/`else` branches; each is reachable within its branch.
+- "Empty catches around color parsing" — **intentional**. These are graceful fallbacks for user-provided custom color strings; failing silently to the theme default is the desired UX.
+
+### `lib-terminal-keyboard/gesture/KeyRepeatHandler.kt`
+- "CoroutineScope not cancelled if `destroy()` never called" — **not a real issue**. `TerminalKeyboard.detach()` calls `keyRepeatHandler.destroy()`, and `detach()` is called from the `DisposableEffect(keyboard)` onDispose in `MainActivity`.
+
+### `lib-ssh/SftpSession.kt`
+- "`sortEntries` sorts dirs by name even in `size` mode" — **intentional**. Directories in SFTP do not have a meaningful file size (usually 0 or filesystem-block size); alphabetical ordering is the sensible fallback.
+- "Dispatcher leak on `connect()` failure" — **false positive**. `SftpSessionManager.openSftpSession` wraps the `connect()` call in try/catch and calls `sftpSession.close()` on failure (line 49), which shuts down the dispatcher.
+
+### `lib-ssh/SSHSession.kt`
+- "Password in `String`" — **known limitation** documented in the existing code. Strings are immutable in the JVM and cannot be reliably zeroed; the app converts them to `CharArray` at the earliest opportunity in `MainViewModel`/`TerminalService` and zeros those. Not a regression.
+- "Swallowed cleanup exceptions" — **intentional**. Cleanup paths swallow to avoid cascading failures that could mask the original disconnect reason.
+
+### `lib-vault-crypto/aes256gcm.c`
+- "Table-based AES vulnerable to cache-timing side channels" — **not in threat model**. The app runs in its own Android process; there is no co-located untrusted code attempting cache-timing attacks against the vault crypto. Using a constant-time software AES would add complexity without addressing a real attack vector.
+- "GHASH not constant-time" — same rationale.
+
+### `lib-vault-crypto/VaultCrypto.kt`
+- "Plaintext ByteArray parameter not zeroed by the Kotlin API" — **caller's responsibility**. The Kotlin API is a thin JNI wrapper; the caller owns the input ByteArray and is expected to zero it after use if it contains secrets. Documenting this would be useful (follow-up doc task), but the code itself is not buggy.
+
+### `lib-terminal-view/ScreenBuffer.kt`
+- "`screenRow()` returns `buf[0]` for out-of-bounds" — **defensive**, not a bug. Parser callers should never hit this path; the fallback prevents a crash in unexpected cases.
+
+### `app/ui/MainActivity.kt`, `MainViewModel.kt`, `SessionTabBar.kt`, `EditConnectionScreen.kt`, `KeyboardSettingsDialog.kt`, `QuickBarCustomizer.kt`
+- All clean per the app-module agent. HW keyboard detection, theme picker, NumBlok serialization all correct.
+
+### `app/src/dev/DevConfig.kt`
+- "Hardcoded test credentials" — **dev flavor only**, stripped from prod. Used for the internal test SSH servers (one.jima.cat, 10.10.0.39). Not a leak.
+
+## Build verification
+
+- `./gradlew assembleDevDebug` — **BUILD SUCCESSFUL** (v0.0.31)
+- Native `vault_crypto.cpp` recompiled cleanly for all ABIs (armeabi-v7a, arm64-v8a, x86, x86_64) with the added `secure_zero` calls.
+- Deployed to `duero:/mnt/master/ssh-workbench.v0.0.31.dev.dbg.2026-04-06.apk`.
+- S23 was disconnected at deploy time, so no install/smoke test on device. Previous v0.0.30 is still installed on S23; the audit changes are all defence-in-depth tightening and should be transparent at runtime.
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@ -30,8 +30,8 @@ android {
    defaultConfig {
        minSdk = 27
        targetSdk = 36
-        versionCode = 20
-        versionName = "0.0.20"
+        versionCode = 31
+        versionName = "0.0.31"

        applicationId = "com.roundingmobile.sshworkbench"
        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
--- a/app/src/main/java/com/roundingmobile/sshworkbench/BuildTimestamp.kt
+++ b/app/src/main/java/com/roundingmobile/sshworkbench/BuildTimestamp.kt
@ -2,5 +2,5 @@ package com.roundingmobile.sshworkbench

 // Auto-generated — do not edit
 object BuildTimestamp {
-    const val TIME = "2026-04-06 11:23:39"
+    const val TIME = "2026-04-06 13:12:27"
 }
--- a/app/src/main/java/com/roundingmobile/sshworkbench/terminal/KeyboardSettingsDialog.kt
+++ b/app/src/main/java/com/roundingmobile/sshworkbench/terminal/KeyboardSettingsDialog.kt
@ -62,7 +62,6 @@ import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.geometry.Size
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.drawscope.Stroke
-import androidx.compose.ui.platform.LocalConfiguration
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.text.TextStyle
@ -756,17 +755,14 @@ private fun KeyboardTab(
            )
        }

-        // Number row mode — mini numpad (left/right) only available in landscape
+        // Number row mode — all four options available in both orientations
        SectionLabel(stringResource(R.string.number_row))
-        val isLandscape = LocalConfiguration.current.orientation == android.content.res.Configuration.ORIENTATION_LANDSCAPE
-        val allNumberRowOptions = listOf(
+        val numberRowOptions = listOf(
            "top" to R.string.number_row_top,
            "left" to R.string.number_row_left,
            "right" to R.string.number_row_right,
            "hidden" to R.string.number_row_hidden
        )
-        val numberRowOptions = if (isLandscape) allNumberRowOptions
-            else allNumberRowOptions.filter { it.first != "left" && it.first != "right" }
        LanguageDropdown(
            options = numberRowOptions.map { it.first to stringResource(it.second) },
            selected = numberRowMode,
--- a/app/src/main/java/com/roundingmobile/sshworkbench/terminal/QuickBarCustomizer.kt
+++ b/app/src/main/java/com/roundingmobile/sshworkbench/terminal/QuickBarCustomizer.kt
@ -203,6 +203,7 @@ private fun serializeAction(action: KeyAction): JSONObject {
        is KeyAction.ToggleMod -> { obj.put("type", "toggle_mod"); obj.put("mod", action.mod) }
        is KeyAction.Macro -> { obj.put("type", "macro"); obj.put("text", action.text) }
        is KeyAction.SwitchPage -> { obj.put("type", "switch_page"); obj.put("pageId", action.pageId) }
+        is KeyAction.ToggleNumBlock -> { obj.put("type", "toggle_numblock") }
        is KeyAction.None -> { obj.put("type", "none") }
    }
    return obj
@ -215,6 +216,7 @@ private fun deserializeAction(obj: JSONObject): KeyAction =
        "esc_seq" -> KeyAction.EscSeq(obj.getString("seq"))
        "combo" -> { val m = obj.getJSONArray("mod"); KeyAction.Combo((0 until m.length()).map { m.getString(it) }, obj.getString("key")) }
        "toggle_mod" -> KeyAction.ToggleMod(obj.getString("mod"))
+        "toggle_numblock" -> KeyAction.ToggleNumBlock
        "macro" -> KeyAction.Macro(obj.getString("text"))
        "switch_page" -> KeyAction.SwitchPage(obj.getString("pageId"))
        else -> KeyAction.None
--- a/app/src/main/java/com/roundingmobile/sshworkbench/ui/MainActivity.kt
+++ b/app/src/main/java/com/roundingmobile/sshworkbench/ui/MainActivity.kt
@ -297,11 +297,17 @@ class MainActivity : AppCompatActivity() {
        val isTablet = LocalContext.current.resources.configuration.smallestScreenWidthDp >= 600
        val sameSizeBoth by mainViewModel.terminalPrefs.keyboardSameSizeBoth.collectAsStateWithLifecycle(!isTablet)
        val isLandscape = LocalConfiguration.current.orientation == android.content.res.Configuration.ORIENTATION_LANDSCAPE
+        // Hardware keyboard detection — Configuration updates live when a BT/USB keyboard
+        // connects or disconnects. When one is attached we default-hide the CKB and QB so
+        // the user sees more terminal. Manual overrides via the kebab menu still work.
+        val hasHwKeyboard = LocalConfiguration.current.keyboard != android.content.res.Configuration.KEYBOARD_NOKEYS &&
+                            LocalConfiguration.current.hardKeyboardHidden != android.content.res.Configuration.HARDKEYBOARDHIDDEN_YES
        val keyboardHeightPercent = if (isLandscape && !sameSizeBoth) keyboardHeightLandscape else keyboardHeightPortrait
        val keyboardLanguage by mainViewModel.terminalPrefs.keyboardLanguage.collectAsStateWithLifecycle("en")
        val showKeyHints by mainViewModel.terminalPrefs.showKeyHints.collectAsStateWithLifecycle(true)
        val numberRowModePref by mainViewModel.terminalPrefs.numberRowMode.collectAsStateWithLifecycle("left")
-        // Mini numpad (left/right) only in landscape — portrait falls back to "top"
+        // Mini numpad is landscape-only by design — portrait always falls back to "top".
+        // NEVER remove this override to "fix" unrelated rotation bugs.
        val numberRowMode = if (!isLandscape && (numberRowModePref == "left" || numberRowModePref == "right")) "top" else numberRowModePref
        val showPageIndicators by mainViewModel.terminalPrefs.showPageIndicators.collectAsStateWithLifecycle(true)
        val cqbSize by mainViewModel.terminalPrefs.quickBarSize.collectAsStateWithLifecycle(42)
@ -325,8 +331,17 @@ class MainActivity : AppCompatActivity() {
        val sessionNavStyle by mainViewModel.terminalPrefs.sessionNavStyle.collectAsStateWithLifecycle("top_bar")
        val isDrawerMode = sessionNavStyle == "drawer"

-        // Temporary hide state — tapping terminal or navigating to terminal resets it
+        // Temporary hide state — tapping terminal or navigating to terminal resets it.
+        // When a hardware keyboard is connected, this flag also gates the QuickBar
+        // (see the QB AndroidView update block below) and defaults to true so CKB+QB
+        // start hidden; user can reveal both via the kebab "Show keyboard" entry.
        var ckbHidden by remember { mutableStateOf(false) }
+        // Reset the ckbHidden state whenever the HW keyboard attach/detach changes:
+        // HW kb connected → hide both by default; HW kb disconnected → show CKB again.
+        // User's manual show/hide between transitions is preserved.
+        androidx.compose.runtime.LaunchedEffect(hasHwKeyboard) {
+            ckbHidden = hasHwKeyboard
+        }
        // Keyboard settings dialog state (opened from CKB gear menu)
        var showKbSettings by remember { mutableStateOf(false) }
        var showAqbSettings by remember { mutableStateOf(false) }
@ -665,7 +680,11 @@ class MainActivity : AppCompatActivity() {
                                }
                                val isTerminalTab = tabTypes[appState.activeSessionId] != TabType.SFTP
                                val qbHidden = qbPosition == "none"
-                                container.visibility = if (quickBarVisible && showTerminal && isTerminalTab && !qbHidden) View.VISIBLE else View.GONE
+                                // When a HW keyboard is active, the kebab Show/Hide toggle
+                                // (ckbHidden) controls both the CKB and the QB as a pair.
+                                // Otherwise the QB follows its own quickBarVisible preference.
+                                val qbShownByUser = if (hasHwKeyboard) !ckbHidden else quickBarVisible
+                                container.visibility = if (qbShownByUser && showTerminal && isTerminalTab && !qbHidden) View.VISIBLE else View.GONE
                                // Set orientation on the actual QuickBarView
                                keyboard.quickBarView?.setOrientation(
                                    if (isVerticalQb) com.roundingmobile.keyboard.model.QuickBarOrientation.VERTICAL
@ -825,6 +844,9 @@ class MainActivity : AppCompatActivity() {
                        },
                        update = { container ->
                            val isTermTab = tabTypes[appState.activeSessionId] != TabType.SFTP
+                            // ckbHidden gates CKB regardless of HW kb — the LaunchedEffect
+                            // above seeds it to hasHwKeyboard so the default is hidden when
+                            // a HW keyboard is connected, but user can still show via kebab.
                            container.visibility = if (isCustomKeyboard && !ckbHidden && showTerminal && isTermTab) android.view.View.VISIBLE else android.view.View.GONE
                            keyboard.setPageIndicatorVisible(showPageIndicators)
                            val screenHeight = container.resources.displayMetrics.heightPixels
--- a/docs/TECHNICAL.md
+++ b/docs/TECHNICAL.md
@ -3,7 +3,7 @@
 > Package: `com.roundingmobile.sshworkbench`
 > Developer: Rounding Mobile Technologies S.L.
 > Min SDK: 27 (Android 8.1) | Target SDK: 36 (Android 16)
-> Last updated: 2026-04-03
+> Last updated: 2026-04-06

 ---

@ -207,6 +207,10 @@ Single Activity host for the entire app. Three-layer Box architecture:
 - **Layer 2**: NavHost (AnimatedVisibility) — ConnectionListScreen, EditConnectionScreen, SettingsScreen, KeyManagerScreen
 - Binds to TerminalService, delegates all state management to MainViewModel

+**Hardware keyboard auto-hide** — `MainActivity` derives `hasHwKeyboard` from `LocalConfiguration.current.keyboard != KEYBOARD_NOKEYS && hardKeyboardHidden != HARDKEYBOARDHIDDEN_YES`. Compose re-observes Configuration live when a BT/USB keyboard connects or disconnects (even with `configChanges` set). A `LaunchedEffect(hasHwKeyboard) { ckbHidden = hasHwKeyboard }` seeds the `ckbHidden` state on every transition, so both the CKB and the QuickBar default-hide when a hardware keyboard is present. The kebab menu's "Show keyboard" toggle controls **both** the CKB and the QuickBar together in HW keyboard mode — the QuickBar `update` block uses `val qbShownByUser = if (hasHwKeyboard) !ckbHidden else quickBarVisible`. In normal (no HW kb) mode the QuickBar follows its own `quickBarVisible` pref unchanged.
+
+**Portrait mini override** — `MainActivity` computes `numberRowMode` as `if (!isLandscape && (pref == "left" || pref == "right")) "top" else pref`. The mini numpad is **landscape-only by design**; portrait always falls back to `top`. Do not remove this override to "fix" unrelated rotation bugs — the mini-in-portrait scenario has been intentionally disabled.
+
 #### `MainViewModel`
 Central ViewModel for the single-Activity architecture:
 - `TabType` enum (`TERMINAL`, `SFTP`) and `SftpTabInfo` data class for SFTP tab metadata
@ -687,6 +691,8 @@ TerminalKeyboard (entry point, Builder)
 └── ModifierStateManager (CTRL/ALT/SHIFT state machine)
 ```

+**VP2 rotation-phantom workaround** — `KeyboardView.onSizeChanged` rebuilds the ViewPager2 (via `buildPages()`) on **any** width transition including the initial `0 → actual` layout pass. The first `buildPages()` happens from `TerminalKeyboard.attachTo()` → `kv.setup()` while the view is still detached (width=0), so VP2's internal RecyclerView scroll offset is unreliable; a second `buildPages()` after the real layout arrives produces a clean result. `KeyboardView.lastModifierStates` caches the current CTRL/ALT/SHIFT state between rebuilds so visual state survives. This works around [Google Issue Tracker 175796502](https://issuetracker.google.com/issues/175796502) which is still unfixed in ViewPager2 1.1.0 for non-`FragmentStateAdapter` usage.
+
 ### Data Models

 **`KeyboardLayout`** — parsed from JSON:
@ -703,9 +709,11 @@ TerminalKeyboard (entry point, Builder)
 }
 ```

-**`KeyDefinition`**: `id`, `label`, `action` (KeyAction), `w/h` (proportional), `style`, `repeatable`, `longPress` (variants), `visible`.
+**`KeyDefinition`**: `id`, `label`, `action` (KeyAction), `w/h` (proportional), `style`, `repeatable`, `longPress` (variants), `visible`, `numLabel` / `numAction` (alternates shown/dispatched when mini NumBlock mode is active).

-**`KeyAction`** (sealed): `Char(primary, shift?)`, `Bytes(values)`, `EscSeq(seq)`, `Combo(mod, key)`, `ToggleMod(mod)`, `Macro(text)`, `SwitchPage(pageId)`, `None`.
+**`KeyAction`** (sealed): `Char(primary, shift?)`, `Bytes(values)`, `EscSeq(seq)`, `Combo(mod, key)`, `ToggleMod(mod)`, `ToggleNumBlock`, `Macro(text)`, `SwitchPage(pageId)`, `None`.
+
+**NumBlok (mini numpad only)**: The mini numpad's last row contains a `toggle_numblock` key. Tapping it flips `TerminalKeyboard.numBlockActive`; while active, `KeyboardPageView.resolveDisplayLabel` returns `key.numLabel` instead of `key.label`, `handleKeyAction` dispatches `key.numAction` instead of `key.action`, and the toggle key itself gets a LOCKED-style amber glow. Mini rows 1-3 become PC-keypad nav (`Home/↑/PgUp`, `←/Esc/→`, `End/↓/PgDn`); `m0` → `Ins`; `m_bslash` → `~`. State is carried across rotation rebuilds via `attachMiniTo` copying `numBlockActive` into the new `KeyboardPageView`. See `project_numblock_mini.md` in auto-memory.

 **`KeyEvent`** (sealed): `Character`, `Bytes`, `EscapeSequence`, `Combo`, `Macro`, `Special`.

--- a/docs/TODO.md
+++ b/docs/TODO.md
@ -33,6 +33,14 @@
 - ~~Vault import in-place~~ — VaultImportSheet hosted in KeysVaultScreen, no popBackStack
 - ~~Clickable radio/checkbox rows~~ — VaultExportSheet, VaultImportSheet rows tappable on text
 - ~~configChanges~~ — orientation|screenSize|smallestScreenSize|screenLayout prevents activity recreation on rotation
+- ~~Theme picker default label~~ — EditConnection + tab bar dialogs now show actual global theme in `Default (…)` label; tab bar dialog uses all 20 themes with scrollable Default option
+- ~~Drawer back button~~ — Back in terminal pane closes drawer first if drawer is open
+- ~~Mini numpad 15% width~~ — `widthPercent` 10 → 15 in all three `layout_qwerty*.json`
+- ~~VP2 rotation phantom fix~~ — `KeyboardView.onSizeChanged` rebuilds VP2 on any width transition including initial 0→actual layout; `lastModifierStates` cached for re-apply (Google Issue 175796502 workaround)
+- ~~Number row dropdown in portrait~~ — `KeyboardSettingsDialog` now shows all 4 options (top/left/right/hidden) regardless of orientation
+- ~~NumBlok toggle on mini numpad~~ — `KeyDefinition.numLabel`/`numAction` fields, `KeyAction.ToggleNumBlock`; mini last row has `Num 0 \` which becomes PC-keypad nav when toggled
+- ~~Hardware keyboard auto-hide~~ — `Configuration.keyboard` detection; CKB + QB hidden by default when BT/USB keyboard connects; kebab Show/Hide toggles both as a pair in HW kb mode
+- ~~Audit 2026-04-06~~ — `KeyboardPageView` smart-cast `!!` removal, `SSHKeyLoader` Ed25519 seed length require, `vault_crypto.cpp` plaintext `secure_zero` before `ReleaseByteArrayElements` in `nativeEncrypt`

 ## Open

--- a/lib-ssh/src/main/java/com/roundingmobile/ssh/SSHKeyLoader.kt
+++ b/lib-ssh/src/main/java/com/roundingmobile/ssh/SSHKeyLoader.kt
@ -98,6 +98,7 @@ object SSHKeyLoader {
     */
    private fun loadEd25519FromPkcs8(info: PrivateKeyInfo): KeyProvider {
        val seed = ASN1OctetString.getInstance(info.parsePrivateKey()).octets
+        require(seed.size == 32) { "Ed25519 seed must be exactly 32 bytes, got ${seed.size}" }
        val edSpec = EdDSANamedCurveTable.getByName("Ed25519")
        val privSpec = EdDSAPrivateKeySpec(seed, edSpec)
        val privKey = EdDSAPrivateKey(privSpec)
--- a/lib-terminal-keyboard/src/main/kotlin/com/roundingmobile/keyboard/TerminalKeyboard.kt
+++ b/lib-terminal-keyboard/src/main/kotlin/com/roundingmobile/keyboard/TerminalKeyboard.kt
@ -278,6 +278,7 @@ class TerminalKeyboard private constructor(
        val page = KeyboardPage(id = "mini", name = "Mini", rows = mini.rows)
        val pv = KeyboardPageView(context, page, theme)
        pv.setOnTouchListener { _, event -> handlePageTouch(pv, event) }
+        pv.numBlockActive = numBlockActive  // carry over across re-attach
        container.addView(pv, ViewGroup.LayoutParams(
            ViewGroup.LayoutParams.MATCH_PARENT,
            ViewGroup.LayoutParams.MATCH_PARENT
@ -810,6 +811,8 @@ class TerminalKeyboard private constructor(
    }

    private fun resolveHintLabel(key: KeyDefinition): String {
+        // Mini NumBlock mode: show the nav label instead of the digit
+        if (numBlockActive && key.numLabel != null) return key.numLabel
        val action = key.action
        if (action is KeyAction.Char && action.shift != null) {
            val shiftState = modifierManager.states.value[Modifier.SHIFT]
@ -822,8 +825,12 @@ class TerminalKeyboard private constructor(

    // --- Action resolution ---

+    /** NumBlock mode flag — toggled by a ToggleNumBlock key, controls the mini numpad's alternate action/label. */
+    private var numBlockActive: Boolean = false
+
    private fun handleKeyAction(key: KeyDefinition) {
-        val action = key.action
+        // If NumBlock is active and the key has a numAction, use that instead of the base action.
+        val action = if (numBlockActive && key.numAction != null) key.numAction else key.action
        val activeModifiers = modifierManager.activeModifiers()
        val shiftActive = Modifier.SHIFT in activeModifiers

@ -870,6 +877,10 @@ class TerminalKeyboard private constructor(
            is KeyAction.SwitchPage -> {
                keyboardView?.switchToPage(action.pageId)
            }
+            is KeyAction.ToggleNumBlock -> {
+                numBlockActive = !numBlockActive
+                miniPageView?.numBlockActive = numBlockActive
+            }
            is KeyAction.None -> {}
        }
    }
--- a/lib-terminal-keyboard/src/main/kotlin/com/roundingmobile/keyboard/model/KeyAction.kt
+++ b/lib-terminal-keyboard/src/main/kotlin/com/roundingmobile/keyboard/model/KeyAction.kt
@ -22,6 +22,9 @@ sealed class KeyAction {
    /** Switch keyboard page. */
    data class SwitchPage(val pageId: String) : KeyAction()

+    /** Toggle the mini numpad's NumBlok mode (keys 1-9 become PC keypad nav keys). */
+    data object ToggleNumBlock : KeyAction()
+
    /** No action — spacer/decorative key. */
    data object None : KeyAction()
 }
--- a/lib-terminal-keyboard/src/main/kotlin/com/roundingmobile/keyboard/model/KeyDefinition.kt
+++ b/lib-terminal-keyboard/src/main/kotlin/com/roundingmobile/keyboard/model/KeyDefinition.kt
@ -21,7 +21,11 @@ data class KeyDefinition(
    val repeatable: Boolean = false,
    val longPress: List<String>? = null,
    val menuItems: List<MenuItem>? = null,
-    val visible: Boolean = true
+    val visible: Boolean = true,
+    /** Alternate label shown when the mini numpad's NumBlok mode is active. */
+    val numLabel: String? = null,
+    /** Alternate action emitted when NumBlok is active (overrides `action`). */
+    val numAction: KeyAction? = null
 ) {
    /** Computed pixel bounds after layout pass — used for hit testing and drawing */
    var bounds: RectF = RectF()
--- a/lib-terminal-keyboard/src/main/kotlin/com/roundingmobile/keyboard/parser/LayoutParser.kt
+++ b/lib-terminal-keyboard/src/main/kotlin/com/roundingmobile/keyboard/parser/LayoutParser.kt
@ -95,7 +95,9 @@ object LayoutParser {
            repeatable = obj.optBoolean("repeatable", false),
            longPress = parseStringList(obj.optJSONArray("longPress")),
            menuItems = parseMenuItems(obj.optJSONArray("menuItems")),
-            visible = obj.optBoolean("visible", true)
+            visible = obj.optBoolean("visible", true),
+            numLabel = obj.optString("numLabel", null),
+            numAction = obj.optJSONObject("numAction")?.let { parseAction(it) }
        )
    }

@ -118,6 +120,7 @@ object LayoutParser {
                )
            }
            "toggle_mod" -> KeyAction.ToggleMod(obj.getString("mod"))
+            "toggle_numblock" -> KeyAction.ToggleNumBlock
            "macro" -> KeyAction.Macro(obj.getString("text"))
            "switch_page" -> KeyAction.SwitchPage(obj.getString("pageId"))
            "none" -> KeyAction.None
--- a/lib-terminal-keyboard/src/main/kotlin/com/roundingmobile/keyboard/view/KeyboardPageView.kt
+++ b/lib-terminal-keyboard/src/main/kotlin/com/roundingmobile/keyboard/view/KeyboardPageView.kt
@ -30,6 +30,10 @@ class KeyboardPageView(
    var modifierStates: Map<Modifier, ModifierState> = emptyMap()
        set(value) { field = value; invalidate() }

+    /** NumBlock mode — when true, keys with a numLabel/numAction render and dispatch those instead. */
+    var numBlockActive: Boolean = false
+        set(value) { field = value; invalidate() }
+
    // Paint objects reused across draws
    private val bgPaint = Paint(Paint.ANTI_ALIAS_FLAG)
    private val borderPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply { style = Paint.Style.STROKE; strokeWidth = 1f }
@ -166,14 +170,19 @@ class KeyboardPageView(
        } else if (modState == ModifierState.LOCKED) {
            canvas.drawRoundRect(rect, radiusPx, radiusPx, lockedPaint)
        }
+        // NumBlock toggle key: LOCKED-style amber glow when active
+        if (key.action is KeyAction.ToggleNumBlock && numBlockActive) {
+            canvas.drawRoundRect(rect, radiusPx, radiusPx, lockedPaint)
+        }

        // Main label — show uppercase when Shift is active
        labelPaint.color = theme.resolveKeyText(key.style)
        labelPaint.isFakeBoldText = pressed
        val displayLabel = resolveDisplayLabel(key)
        val fm = labelPaint.fontMetrics
-        val hasCornerHint = key.hint != null && key.hintColor != 0
-        val hasBelowHint = key.hint != null && key.hintColor == 0
+        val hintText = key.hint  // capture once so smart-cast works through the render branches
+        val hasCornerHint = hintText != null && key.hintColor != 0
+        val hasBelowHint = hintText != null && key.hintColor == 0
        val labelY = if (hasBelowHint) {
            // Label + hint below: label in upper portion, hint below
            val totalH = -fm.ascent + fm.descent + hintPaint.textSize
@ -186,27 +195,29 @@ class KeyboardPageView(
        canvas.drawText(displayLabel, rect.centerX(), labelY, labelPaint)

        // Hint label
-        if (hasBelowHint) {
+        if (hintText != null && hasBelowHint) {
            hintPaint.color = theme.keyHintText
            val hintFm = hintPaint.fontMetrics
            val hintY = labelY + fm.descent + (-hintFm.ascent)
-            canvas.drawText(key.hint!!, rect.centerX(), hintY, hintPaint)
-        } else if (hasCornerHint) {
+            canvas.drawText(hintText, rect.centerX(), hintY, hintPaint)
+        } else if (hintText != null && hasCornerHint) {
            // Corner hint: top-right of key, smaller font
            hintPaint.color = key.hintColor
            hintPaint.textAlign = Paint.Align.RIGHT
            val hintFm = hintPaint.fontMetrics
            val hintY = rect.top + paddingPx - hintFm.ascent
-            canvas.drawText(key.hint!!, rect.right - paddingPx, hintY, hintPaint)
+            canvas.drawText(hintText, rect.right - paddingPx, hintY, hintPaint)
            hintPaint.textAlign = Paint.Align.CENTER // restore
        }
    }

    /**
-     * Returns the label to display, respecting Shift state.
-     * When Shift is ARMED or LOCKED, character keys show their uppercase/shift variant.
+     * Returns the label to display, respecting NumBlock and Shift state.
+     * When NumBlock is active and the key has a numLabel, it wins over the base label and Shift.
+     * When Shift is ARMED/LOCKED, character keys show their uppercase/shift variant.
     */
    private fun resolveDisplayLabel(key: KeyDefinition): String {
+        if (numBlockActive && key.numLabel != null) return key.numLabel
        val action = key.action
        if (action is KeyAction.Char && action.shift != null) {
            val shiftState = modifierStates[Modifier.SHIFT]
--- a/lib-terminal-keyboard/src/main/kotlin/com/roundingmobile/keyboard/view/KeyboardView.kt
+++ b/lib-terminal-keyboard/src/main/kotlin/com/roundingmobile/keyboard/view/KeyboardView.kt
@ -189,7 +189,54 @@ class KeyboardView(context: Context) : FrameLayout(context) {
    fun getPageCount(): Int = realPageCount
    fun getCurrentPageIndex(): Int = currentRealIndex

+    /** Cached modifier states so we can re-apply them after a full VP2 rebuild in onSizeChanged. */
+    private var lastModifierStates: Map<Modifier, ModifierState> = emptyMap()
+
+    /**
+     * Google Issue Tracker 175796502 — after the ViewPager2's width changes (rotation
+     * when Activity has configChanges=orientation, split-screen resize, etc.) its
+     * internal RecyclerView ends up at a fractional scroll offset, leaving the neighbor
+     * page bleeding in from the side. Confirmed still unfixed in VP2 1.1.0.
+     *
+     * Softer workarounds tried and confirmed ineffective:
+     *   - setCurrentItem(currentItem, false) — no-op (VP2 early-returns when item==current)
+     *   - LinearLayoutManager.scrollToPositionWithOffset(currentItem, 0) — runs, but
+     *     VP2's own post-measure logic and the cached RV children override it; phantom
+     *     stays on screen (verified on S23 with logcat proving the call fires).
+     *
+     * Nuclear fix: fully rebuild the ViewPager2 from scratch. Same code path as fresh
+     * launch, which we know produces a correct layout. Cost is a single extra layout
+     * pass on rotation — invisible to the user.
+     */
+    /**
+     * Rebuild the ViewPager2 on every width change, including the initial 0→actual layout
+     * pass. The first buildPages() (triggered from setup()) happens before the view has
+     * real dimensions (w=0), so VP2 is created with zero-width pages. When a size later
+     * arrives, VP2 does not reliably re-anchor its scroll offset — the neighbor page
+     * leaks in from the side (Google Issue Tracker 175796502, still unfixed in VP2 1.1.0
+     * for non-FragmentStateAdapter usage). A second buildPages() at the real dimensions
+     * produces a clean layout regardless of VP2's broken resize path.
+     *
+     * The cost is one extra VP2 construction on startup and on every genuine resize —
+     * cheap (3 pages, Canvas-drawn). The previous KeyboardView instance's modifier states
+     * are re-applied from the cached `lastModifierStates` field.
+     */
+    override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
+        super.onSizeChanged(w, h, oldw, oldh)
+        if (w > 0 && w != oldw && layout != null) {
+            val savedIdx = currentRealIndex
+            post {
+                buildPages()
+                if (lastModifierStates.isNotEmpty()) {
+                    for (pv in allPageViews) pv.modifierStates = lastModifierStates
+                }
+                if (savedIdx > 0) switchToPage(savedIdx)
+            }
+        }
+    }
+
    fun setModifierStates(states: Map<Modifier, ModifierState>) {
+        lastModifierStates = states
        for (pv in allPageViews) {
            pv.modifierStates = states
        }
--- a/lib-terminal-keyboard/src/main/res/raw/layout_qwerty.json
+++ b/lib-terminal-keyboard/src/main/res/raw/layout_qwerty.json
@ -205,22 +205,35 @@
    "widthPercent": 15,
    "rows": [
      { "keys": [
-        { "id": "m1", "label": "1", "action": { "type": "char", "primary": "1", "shift": "!" } },
-        { "id": "m2", "label": "2", "action": { "type": "char", "primary": "2", "shift": "@" } },
-        { "id": "m3", "label": "3", "action": { "type": "char", "primary": "3", "shift": "#" } }
+        { "id": "m1", "label": "1", "action": { "type": "char", "primary": "1", "shift": "!" },
+          "numLabel": "End", "numAction": { "type": "esc_seq", "seq": "[F" } },
+        { "id": "m2", "label": "2", "action": { "type": "char", "primary": "2", "shift": "@" },
+          "numLabel": "↓", "numAction": { "type": "esc_seq", "seq": "[B" } },
+        { "id": "m3", "label": "3", "action": { "type": "char", "primary": "3", "shift": "#" },
+          "numLabel": "PgDn", "numAction": { "type": "esc_seq", "seq": "[6~" } }
      ]},
      { "keys": [
-        { "id": "m4", "label": "4", "action": { "type": "char", "primary": "4", "shift": "$" } },
-        { "id": "m5", "label": "5", "action": { "type": "char", "primary": "5", "shift": "%" } },
-        { "id": "m6", "label": "6", "action": { "type": "char", "primary": "6", "shift": "^" } }
+        { "id": "m4", "label": "4", "action": { "type": "char", "primary": "4", "shift": "$" },
+          "numLabel": "←", "numAction": { "type": "esc_seq", "seq": "[D" } },
+        { "id": "m5", "label": "5", "action": { "type": "char", "primary": "5", "shift": "%" },
+          "numLabel": "Esc", "numAction": { "type": "bytes", "value": [27] } },
+        { "id": "m6", "label": "6", "action": { "type": "char", "primary": "6", "shift": "^" },
+          "numLabel": "→", "numAction": { "type": "esc_seq", "seq": "[C" } }
      ]},
      { "keys": [
-        { "id": "m7", "label": "7", "action": { "type": "char", "primary": "7", "shift": "&" } },
-        { "id": "m8", "label": "8", "action": { "type": "char", "primary": "8", "shift": "*" } },
-        { "id": "m9", "label": "9", "action": { "type": "char", "primary": "9", "shift": "(" } }
+        { "id": "m7", "label": "7", "action": { "type": "char", "primary": "7", "shift": "&" },
+          "numLabel": "Home", "numAction": { "type": "esc_seq", "seq": "[H" } },
+        { "id": "m8", "label": "8", "action": { "type": "char", "primary": "8", "shift": "*" },
+          "numLabel": "↑", "numAction": { "type": "esc_seq", "seq": "[A" } },
+        { "id": "m9", "label": "9", "action": { "type": "char", "primary": "9", "shift": "(" },
+          "numLabel": "PgUp", "numAction": { "type": "esc_seq", "seq": "[5~" } }
      ]},
      { "keys": [
-        { "id": "m0", "label": "0", "action": { "type": "char", "primary": "0", "shift": ")" } }
+        { "id": "m_numblock", "label": "Num", "action": { "type": "toggle_numblock" }, "style": "modifier" },
+        { "id": "m0", "label": "0", "action": { "type": "char", "primary": "0", "shift": ")" },
+          "numLabel": "Ins", "numAction": { "type": "esc_seq", "seq": "[2~" } },
+        { "id": "m_bslash", "label": "\\", "action": { "type": "char", "primary": "\\", "shift": "|" },
+          "numLabel": "~", "numAction": { "type": "char", "primary": "~" } }
      ]}
    ]
  },
--- a/lib-terminal-keyboard/src/main/res/raw/layout_qwerty_es.json
+++ b/lib-terminal-keyboard/src/main/res/raw/layout_qwerty_es.json
@ -206,22 +206,35 @@
    "widthPercent": 15,
    "rows": [
      { "keys": [
-        { "id": "m1", "label": "1", "action": { "type": "char", "primary": "1", "shift": "!" } },
-        { "id": "m2", "label": "2", "action": { "type": "char", "primary": "2", "shift": "@" } },
-        { "id": "m3", "label": "3", "action": { "type": "char", "primary": "3", "shift": "#" } }
+        { "id": "m1", "label": "1", "action": { "type": "char", "primary": "1", "shift": "!" },
+          "numLabel": "End", "numAction": { "type": "esc_seq", "seq": "[F" } },
+        { "id": "m2", "label": "2", "action": { "type": "char", "primary": "2", "shift": "@" },
+          "numLabel": "↓", "numAction": { "type": "esc_seq", "seq": "[B" } },
+        { "id": "m3", "label": "3", "action": { "type": "char", "primary": "3", "shift": "#" },
+          "numLabel": "PgDn", "numAction": { "type": "esc_seq", "seq": "[6~" } }
      ]},
      { "keys": [
-        { "id": "m4", "label": "4", "action": { "type": "char", "primary": "4", "shift": "$" } },
-        { "id": "m5", "label": "5", "action": { "type": "char", "primary": "5", "shift": "%" } },
-        { "id": "m6", "label": "6", "action": { "type": "char", "primary": "6", "shift": "^" } }
+        { "id": "m4", "label": "4", "action": { "type": "char", "primary": "4", "shift": "$" },
+          "numLabel": "←", "numAction": { "type": "esc_seq", "seq": "[D" } },
+        { "id": "m5", "label": "5", "action": { "type": "char", "primary": "5", "shift": "%" },
+          "numLabel": "Esc", "numAction": { "type": "bytes", "value": [27] } },
+        { "id": "m6", "label": "6", "action": { "type": "char", "primary": "6", "shift": "^" },
+          "numLabel": "→", "numAction": { "type": "esc_seq", "seq": "[C" } }
      ]},
      { "keys": [
-        { "id": "m7", "label": "7", "action": { "type": "char", "primary": "7", "shift": "&" } },
-        { "id": "m8", "label": "8", "action": { "type": "char", "primary": "8", "shift": "*" } },
-        { "id": "m9", "label": "9", "action": { "type": "char", "primary": "9", "shift": "(" } }
+        { "id": "m7", "label": "7", "action": { "type": "char", "primary": "7", "shift": "&" },
+          "numLabel": "Home", "numAction": { "type": "esc_seq", "seq": "[H" } },
+        { "id": "m8", "label": "8", "action": { "type": "char", "primary": "8", "shift": "*" },
+          "numLabel": "↑", "numAction": { "type": "esc_seq", "seq": "[A" } },
+        { "id": "m9", "label": "9", "action": { "type": "char", "primary": "9", "shift": "(" },
+          "numLabel": "PgUp", "numAction": { "type": "esc_seq", "seq": "[5~" } }
      ]},
      { "keys": [
-        { "id": "m0", "label": "0", "action": { "type": "char", "primary": "0", "shift": ")" } }
+        { "id": "m_numblock", "label": "Num", "action": { "type": "toggle_numblock" }, "style": "modifier" },
+        { "id": "m0", "label": "0", "action": { "type": "char", "primary": "0", "shift": ")" },
+          "numLabel": "Ins", "numAction": { "type": "esc_seq", "seq": "[2~" } },
+        { "id": "m_bslash", "label": "\\", "action": { "type": "char", "primary": "\\", "shift": "|" },
+          "numLabel": "~", "numAction": { "type": "char", "primary": "~" } }
      ]}
    ]
  },
--- a/lib-terminal-keyboard/src/main/res/raw/layout_qwerty_sv.json
+++ b/lib-terminal-keyboard/src/main/res/raw/layout_qwerty_sv.json
@ -208,22 +208,35 @@
    "widthPercent": 15,
    "rows": [
      { "keys": [
-        { "id": "m1", "label": "1", "action": { "type": "char", "primary": "1", "shift": "!" } },
-        { "id": "m2", "label": "2", "action": { "type": "char", "primary": "2", "shift": "@" } },
-        { "id": "m3", "label": "3", "action": { "type": "char", "primary": "3", "shift": "#" } }
+        { "id": "m1", "label": "1", "action": { "type": "char", "primary": "1", "shift": "!" },
+          "numLabel": "End", "numAction": { "type": "esc_seq", "seq": "[F" } },
+        { "id": "m2", "label": "2", "action": { "type": "char", "primary": "2", "shift": "@" },
+          "numLabel": "↓", "numAction": { "type": "esc_seq", "seq": "[B" } },
+        { "id": "m3", "label": "3", "action": { "type": "char", "primary": "3", "shift": "#" },
+          "numLabel": "PgDn", "numAction": { "type": "esc_seq", "seq": "[6~" } }
      ]},
      { "keys": [
-        { "id": "m4", "label": "4", "action": { "type": "char", "primary": "4", "shift": "$" } },
-        { "id": "m5", "label": "5", "action": { "type": "char", "primary": "5", "shift": "%" } },
-        { "id": "m6", "label": "6", "action": { "type": "char", "primary": "6", "shift": "^" } }
+        { "id": "m4", "label": "4", "action": { "type": "char", "primary": "4", "shift": "$" },
+          "numLabel": "←", "numAction": { "type": "esc_seq", "seq": "[D" } },
+        { "id": "m5", "label": "5", "action": { "type": "char", "primary": "5", "shift": "%" },
+          "numLabel": "Esc", "numAction": { "type": "bytes", "value": [27] } },
+        { "id": "m6", "label": "6", "action": { "type": "char", "primary": "6", "shift": "^" },
+          "numLabel": "→", "numAction": { "type": "esc_seq", "seq": "[C" } }
      ]},
      { "keys": [
-        { "id": "m7", "label": "7", "action": { "type": "char", "primary": "7", "shift": "&" } },
-        { "id": "m8", "label": "8", "action": { "type": "char", "primary": "8", "shift": "*" } },
-        { "id": "m9", "label": "9", "action": { "type": "char", "primary": "9", "shift": "(" } }
+        { "id": "m7", "label": "7", "action": { "type": "char", "primary": "7", "shift": "&" },
+          "numLabel": "Home", "numAction": { "type": "esc_seq", "seq": "[H" } },
+        { "id": "m8", "label": "8", "action": { "type": "char", "primary": "8", "shift": "*" },
+          "numLabel": "↑", "numAction": { "type": "esc_seq", "seq": "[A" } },
+        { "id": "m9", "label": "9", "action": { "type": "char", "primary": "9", "shift": "(" },
+          "numLabel": "PgUp", "numAction": { "type": "esc_seq", "seq": "[5~" } }
      ]},
      { "keys": [
-        { "id": "m0", "label": "0", "action": { "type": "char", "primary": "0", "shift": ")" } }
+        { "id": "m_numblock", "label": "Num", "action": { "type": "toggle_numblock" }, "style": "modifier" },
+        { "id": "m0", "label": "0", "action": { "type": "char", "primary": "0", "shift": ")" },
+          "numLabel": "Ins", "numAction": { "type": "esc_seq", "seq": "[2~" } },
+        { "id": "m_bslash", "label": "\\", "action": { "type": "char", "primary": "\\", "shift": "|" },
+          "numLabel": "~", "numAction": { "type": "char", "primary": "~" } }
      ]}
    ]
  },
--- a/lib-vault-crypto/src/main/cpp/vault_crypto.cpp
+++ b/lib-vault-crypto/src/main/cpp/vault_crypto.cpp
@ -137,6 +137,7 @@ Java_com_roundingmobile_vaultcrypto_VaultCrypto_nativeEncrypt(
    jbyte *keyPtr = env->GetByteArrayElements(key, nullptr);
    if (!keyPtr) {
        LOGE("Failed to get key bytes");
+        secure_zero(ptPtr, ptLen);
        env->ReleaseByteArrayElements(plaintext, ptPtr, JNI_ABORT);
        return nullptr;
    }
@ -149,6 +150,7 @@ Java_com_roundingmobile_vaultcrypto_VaultCrypto_nativeEncrypt(
        LOGE("Failed to read /dev/urandom");
        if (urandom) fclose(urandom);
        secure_zero(keyPtr, keyLen);
+        secure_zero(ptPtr, ptLen);
        env->ReleaseByteArrayElements(plaintext, ptPtr, JNI_ABORT);
        env->ReleaseByteArrayElements(key, keyPtr, JNI_ABORT);
        return nullptr;
@ -173,6 +175,7 @@ Java_com_roundingmobile_vaultcrypto_VaultCrypto_nativeEncrypt(
    secure_zero(tag, sizeof(tag));
    secure_zero(nonce, sizeof(nonce));
    secure_zero(keyPtr, keyLen);
+    secure_zero(ptPtr, ptLen);  // plaintext in the JNI copy — defence-in-depth
    env->ReleaseByteArrayElements(plaintext, ptPtr, JNI_ABORT);
    env->ReleaseByteArrayElements(key, keyPtr, JNI_ABORT);