feat(subtitles): add local Japanese subtitle generation

- Generate Japanese SRTs through the overlay modal or launcher
- Support managed whisper.cpp models and optional dialogue detection

src/config/resolve/core-domains.ts

@@ -237,6 +237,7 @@ export function applyCoreDomainConfig(context: ResolveContext): void {
       'openRuntimeOptions',
       'openJimaku',
       'openTsukihime',
+      'openSubtitleGeneration',
       'openSessionHelp',
       'openControllerSelect',
       'openControllerDebug',

src/config/resolve/subtitle-domains.ts

@@ -1,5 +1,6 @@
 import { ResolvedConfig } from '../../types/config';
 import { ResolveContext } from './context';
+import { resolveSubtitleGenerationConfig } from '../../shared/subtitle-generation';
 import {
   asBoolean,
   asColor,
@@ -46,6 +47,17 @@ function applySubtitleHoverTokenCssCompatibility(
 
 export function applySubtitleDomainConfig(context: ResolveContext): void {
   const { src, resolved, warn } = context;
+  resolved.subtitleGeneration = resolveSubtitleGenerationConfig(
+    src.subtitleGeneration,
+    (key, value, message) => {
+      const configPath = key === 'subtitleGeneration' ? key : `subtitleGeneration.${key}`;
+      const fallback =
+        key === 'subtitleGeneration'
+          ? resolved.subtitleGeneration
+          : Object.entries(resolved.subtitleGeneration).find(([name]) => name === key)?.[1];
+      warn(configPath, value, fallback, message);
+    },
+  );
 
   if (isObject(src.jimaku)) {
     const apiKey = asString(src.jimaku.apiKey);

src/config/resolve/subtitle-generation.test.ts

@@ -0,0 +1,90 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { resolveConfig } from '../resolve';
+import { buildConfigSettingsRegistry } from '../settings/registry';
+import { SUBTITLE_GENERATION_MODELS } from '../../shared/subtitle-generation-model-catalog';
+import { resolveSubtitleGenerationConfig } from '../../shared/subtitle-generation';
+
+test('every downloadable multilingual model is accepted by config and offered in settings', () => {
+  const settings = buildConfigSettingsRegistry(resolveConfig({}).resolved).find(
+    (entry) => entry.configPath === 'subtitleGeneration.managedModel',
+  );
+  assert.deepEqual(
+    settings?.enumValues,
+    SUBTITLE_GENERATION_MODELS.map((model) => model.id),
+  );
+  for (const { id } of SUBTITLE_GENERATION_MODELS) {
+    const { resolved, warnings } = resolveConfig({ subtitleGeneration: { managedModel: id } });
+    assert.equal(resolved.subtitleGeneration.managedModel, id);
+    assert.equal(warnings.length, 0);
+  }
+});
+
+test('generation config rejects English-only, unknown, and prototype model names', () => {
+  for (const managedModel of ['tiny.en', 'small.en-q5_1', 'unknown', 'toString', '__proto__']) {
+    const warnings: string[] = [];
+    const resolved = resolveSubtitleGenerationConfig({ managedModel }, (key) => warnings.push(key));
+    assert.equal(resolved.managedModel, 'small');
+    assert.equal(warnings.length, 1);
+  }
+});
+
+test('generation config is resolved and its external model path is editable without restart', () => {
+  const { resolved, warnings } = resolveConfig({
+    subtitleGeneration: { modelPath: '/models/japanese.bin', managedModel: 'medium', threads: 8 },
+  });
+  assert.equal(resolved.subtitleGeneration.modelPath, '/models/japanese.bin');
+  assert.equal(resolved.subtitleGeneration.managedModel, 'medium');
+  assert.equal(warnings.length, 0);
+  const field = buildConfigSettingsRegistry(resolved).find(
+    (entry) => entry.configPath === 'subtitleGeneration.modelPath',
+  );
+  assert.equal(field?.category, 'integrations');
+  assert.equal(field?.restartBehavior, 'hot-reload');
+});
+
+test('generation executable overrides default to empty and accept blank values without warnings', () => {
+  for (const subtitleGeneration of [
+    {},
+    { whisperPath: '', ffmpegPath: '', ffprobePath: '' },
+    { whisperPath: '  ', ffmpegPath: '  ', ffprobePath: '  ' },
+  ]) {
+    const { resolved, warnings } = resolveConfig({ subtitleGeneration });
+    assert.equal(resolved.subtitleGeneration.whisperPath, '');
+    assert.equal(resolved.subtitleGeneration.ffmpegPath, '');
+    assert.equal(resolved.subtitleGeneration.ffprobePath, '');
+    assert.equal(warnings.length, 0);
+  }
+});
+
+test('subtitle generation shortcut can be customized or disabled', () => {
+  assert.equal(resolveConfig({}).resolved.shortcuts.openSubtitleGeneration, 'Ctrl+Shift+G');
+  assert.equal(
+    resolveConfig({ shortcuts: { openSubtitleGeneration: 'Ctrl+Alt+G' } }).resolved.shortcuts
+      .openSubtitleGeneration,
+    'Ctrl+Alt+G',
+  );
+  assert.equal(
+    resolveConfig({ shortcuts: { openSubtitleGeneration: null } }).resolved.shortcuts
+      .openSubtitleGeneration,
+    null,
+  );
+});
+
+test('dialogue detection paths are optional, validated, and editable in Settings', () => {
+  const { resolved, warnings } = resolveConfig({
+    subtitleGeneration: { vadModelPath: ' /models/silero.bin ', vadPath: ' /bin/vad ' },
+  });
+  assert.equal(resolved.subtitleGeneration.vadModelPath, '/models/silero.bin');
+  assert.equal(resolved.subtitleGeneration.vadPath, '/bin/vad');
+  assert.equal(warnings.length, 0);
+  for (const key of ['vadModelPath', 'vadPath'] as const) {
+    const field = buildConfigSettingsRegistry(resolved).find(
+      (entry) => entry.configPath === `subtitleGeneration.${key}`,
+    );
+    assert.equal(field?.category, 'integrations');
+    assert.equal(field?.restartBehavior, 'hot-reload');
+    assert.equal(resolveConfig({}).resolved.subtitleGeneration[key], '');
+    assert.equal(resolveConfig({ subtitleGeneration: { [key]: false } }).warnings.length, 1);
+  }
+});