Merge branch 'feature/intelligent-polish-and-personal-dict' into main

Resolved real conflicts introduced by translation-polish-2 (#3) and
docs refresh (#4) being merged to main during development:

- OSGKeyboardShared/Models/ProviderConfig.swift
  Add polishIntensity field alongside translationTargetLocaleId /
  polishScenarioId / handednessPreference. Both new fields coexist.

- OSGKeyboardShared/Services/AppGroupStore.swift
  Keep main's translation setters; add polishIntensity setter,
  detectedAppContext setter, and personalDictionary getter/setter.

- OSGKeyboardShared/Services/PolishingService.swift
  Merge v0.2.1 translate-and-polish path with v0.3.0 context-aware
  intelligent prompt. New polish() entry point accepts both modes;
  translation mode still uses TranslationPrompt, polish mode now
  uses buildPrompt(for:context:).

- OSGKeyboard/Views/SettingsView.swift
  Compose localEngineSettingsSection (main) with polishIntensitySection,
  languageAndModelsSection, systemPromptLinkSection, personalDictionaryLinkSection (feature).

- OSGKeyboardShared/{en,zh-Hans}.lproj/Shared.strings
  Concat scenario keys + polish intensity / app context / dictionary keys.

Auto-merged without conflict:
- AppGroupStore new methods (localASRBackend, etc.)
- FlowSessionManager, KeyboardViewController (auto-merged)
- MaterialIcon, HistoryView (auto-merged, my icons added on top)

Co-authored-by: Mavis <Mavis@hkgood.dev>

OSGKeyboardShared/Models/ProviderConfig.swift

@@ -53,6 +53,8 @@ public final class ProviderConfig: ObservableObject, @unchecked Sendable {
         static let translationTargetLocaleId = "config.translationTargetLocaleId"
         static let polishScenarioId = "config.polishScenarioId"
         static let handednessPreference = "config.handednessPreference"
+        // v0.3.0: how aggressively the LLM should rewrite transcripts.
+        static let polishIntensity = "config.polishIntensity"
     }
 
     @Published public var providerId: String {
@@ -201,6 +203,14 @@ public final class ProviderConfig: ObservableObject, @unchecked Sendable {
         PolishScenarioCatalog.isCustom(polishScenarioId)
     }
 
+    /// v0.3.0: how aggressively the LLM should rewrite the ASR
+    /// transcript. Default is `medium` (Typeless-equivalent). The
+    /// `off` value never calls the LLM — equivalent to "transcribe
+    /// only" regardless of `engineMode`.
+    @Published public var polishIntensity: PolishIntensity {
+        didSet { defaults.set(polishIntensity.rawValue, forKey: Key.polishIntensity) }
+    }
+
     public var isConfigured: Bool {
         // Local engine (on-device ASR only) doesn't need an API key,
         // base URL, or model — the LLM round-trip is skipped entirely.
@@ -311,6 +321,15 @@ public final class ProviderConfig: ObservableObject, @unchecked Sendable {
         self.handednessPreference = HandednessPreference.fromStored(
             resolvedDefaults.string(forKey: Key.handednessPreference)
         )
+        // v0.3.0: polish intensity. Default to `.medium` for new
+        // installs and upgrades; the existing `off` / `light` /
+        // `heavy` values are honored.
+        if let raw = resolvedDefaults.string(forKey: Key.polishIntensity),
+           let intensity = PolishIntensity(rawValue: raw) {
+            self.polishIntensity = intensity
+        } else {
+            self.polishIntensity = .default
+        }
 
         // Cloud no longer exposes off/transcribe; migrate legacy values.
         if self.engineMode == "cloud", self.modeId != "polish" {