feat: cursor navigation, key sounds, dictionary tooling, key security

Batch of in-progress app work from the working tree.

- feat(keyboard): CursorNavigation + CursorDragPad for caret movement;
  KeyboardSoundFeedback for system key click sounds
- feat(dictionary): DictionaryAliasGenerator + PersonalDictionaryEntrySheet;
  TranscriptPostProcessor quality gate; retire DictionaryLearner
- feat(ui): TabBarVisibility handling; drop PageHeaderRow /
  PageHeaderConfirmButton; refresh views and localizable strings
- fix(security): move the hardcoded DeepSeek key out of
  PreconfiguredKeys.swift into a gitignored PreconfiguredKeys.local.swift
  (seeded from .example by generate-xcodeproj.sh)
- docs(agents): add Conventional Commits versioning + bilingual changelog rules
- chore(gitignore): ignore PreconfiguredKeys.local.swift, .cache/, pycache

Custom language model / lexicon work stays on
feature/custom-language-model-asr. Changelog bullets added under
[Unreleased]; no version bump.

OSGKeyboardExt/Services/AppGroupPersistor.swift

@@ -41,7 +41,12 @@ public struct AppGroupPersistor {
         // the keyboard stays open.
         state.translationTargetLocaleId = store.translationTargetLocaleId
         state.handednessPreference = store.handednessPreference
+        state.cursorDragNavigationEnabled = store.cursorDragNavigationEnabled
         state.localModeCloudPolishEnabled = store.localModeCloudPolishEnabled
+        state.micDisabled = store.isCloudAPIKeyMissingForVoiceInput
+        state.micDisabledHint = store.isCloudAPIKeyMissingForVoiceInput
+            ? ExtL10n.string("keyboard.mic.disabled.missingApiKey")
+            : ""
         // v0.2.0: iOS `SpeechAnalyzer` is always ready; mirror that
         // into the State flags so downstream consumers see the same
         // shape they did when the previous Qwen3 stack reported "ready".
@@ -95,6 +100,11 @@ public struct AppGroupPersistor {
             state.translationTargetLocaleId = store.translationTargetLocaleId
         }
         state.handednessPreference = store.handednessPreference
+        state.cursorDragNavigationEnabled = store.cursorDragNavigationEnabled
+        state.micDisabled = store.isCloudAPIKeyMissingForVoiceInput
+        state.micDisabledHint = store.isCloudAPIKeyMissingForVoiceInput
+            ? ExtL10n.string("keyboard.mic.disabled.missingApiKey")
+            : ""
         // v0.2.0: iOS `SpeechAnalyzer` is always ready. Keep these
         // toggles here so the keyboard UI doesn't flicker if the host
         // app briefly clears them while refactoring.