feat(subtitles): add local Japanese subtitle generation (#240)

src/config/definitions/defaults-core.ts

@@ -99,6 +99,7 @@ export const CORE_DEFAULT_CONFIG: Pick<
     openRuntimeOptions: 'CommandOrControl+Shift+O',
     openJimaku: 'Ctrl+Shift+J',
     openTsukihime: 'Ctrl+Shift+T',
+    openSubtitleGeneration: 'Ctrl+Shift+G',
     openSessionHelp: 'CommandOrControl+Slash',
     openControllerSelect: 'Alt+C',
     openControllerDebug: 'Alt+Shift+C',

src/config/definitions/options-core.ts

@@ -628,6 +628,12 @@ export function buildCoreConfigOptionRegistry(
       defaultValue: defaultConfig.shortcuts.openSessionHelp,
       description: 'Accelerator that opens the session help / keybinding cheatsheet.',
     },
+    {
+      path: 'shortcuts.openSubtitleGeneration',
+      kind: 'string',
+      defaultValue: defaultConfig.shortcuts.openSubtitleGeneration,
+      description: 'Accelerator that opens the standalone Japanese subtitle generation modal.',
+    },
     {
       path: 'shortcuts.openControllerSelect',
       kind: 'string',

src/config/definitions/options-subtitle.ts

@@ -1,10 +1,46 @@
 import { ResolvedConfig } from '../../types/config';
 import { ConfigOptionRegistryEntry } from './shared';
+import { SUBTITLE_GENERATION_MODELS } from '../../shared/subtitle-generation-model-catalog';
 
 export function buildSubtitleConfigOptionRegistry(
   defaultConfig: ResolvedConfig,
 ): ConfigOptionRegistryEntry[] {
   return [
+    ...(
+      ['whisperPath', 'modelPath', 'ffmpegPath', 'ffprobePath', 'vadModelPath', 'vadPath'] as const
+    ).map((key) => ({
+      path: `subtitleGeneration.${key}`,
+      kind: 'string' as const,
+      defaultValue: defaultConfig.subtitleGeneration[key],
+      description: {
+        whisperPath:
+          'Optional path override for whisper.cpp. Leave empty to find whisper-cli on PATH.',
+        modelPath:
+          'Path to an existing multilingual whisper.cpp GGML model. Leave empty to use a SubMiner-managed model. A configured path always takes precedence.',
+        ffmpegPath:
+          'Optional FFmpeg path override for audio extraction. Leave empty to find ffmpeg on PATH.',
+        ffprobePath:
+          'Optional FFprobe path override for audio tracks and timing. Leave empty to find ffprobe on PATH.',
+        vadModelPath:
+          'Path to a whisper.cpp Silero VAD model. Enables dialogue-focused generation while retaining uncertain audible sections, which may include songs. Leave empty to transcribe the full audio.',
+        vadPath:
+          'Optional speech detector executable override. With vadModelPath configured, leave empty to find whisper-vad-speech-segments or vad-speech-segments on PATH.',
+      }[key],
+    })),
+    {
+      path: 'subtitleGeneration.managedModel',
+      kind: 'enum',
+      enumValues: SUBTITLE_GENERATION_MODELS.map((model) => model.id),
+      defaultValue: defaultConfig.subtitleGeneration.managedModel,
+      description:
+        'Multilingual whisper.cpp model to use when modelPath is empty. Download it explicitly from the generation modal or launcher.',
+    },
+    {
+      path: 'subtitleGeneration.threads',
+      kind: 'number',
+      defaultValue: defaultConfig.subtitleGeneration.threads,
+      description: 'Positive integer CPU thread count for whisper.cpp Japanese transcription.',
+    },
     {
       path: 'subtitleStyle.primaryDefaultMode',
       kind: 'enum',

src/config/definitions/template-sections.ts

@@ -1,6 +1,15 @@
 import { ConfigTemplateSection } from './shared';
 
 const CORE_TEMPLATE_SECTIONS: ConfigTemplateSection[] = [
+  {
+    title: 'Japanese Subtitle Generation',
+    description: [
+      'Generate timed Japanese subtitles from local audio using whisper.cpp.',
+      'Configure an existing GGML model path or explicitly download a SubMiner-managed model.',
+    ],
+    notes: ['Hot-reload: settings apply to the next generation or model download.'],
+    key: 'subtitleGeneration',
+  },
   {
     title: 'Visible Overlay Auto-Start',
     description: [