refactor: remove dead code and enable noUnusedLocals (#292)

* refactor: remove dead code and enable noUnusedLocals

- delete launcher/jimaku.ts and the launcher Args/config jimaku* fields
  that only fed it (the SUBMINER_JIMAKU_* env vars had no effect)
- delete plugin/subminer/hover.lua; nothing has sent subminer-hover-token
  since Overlay 2.0
- drop never-read anilist.characterDictionary.refreshTtlHours and
  evictionPolicy (still hidden in the settings UI for old configs)
- drop unused root deps: eslint, @fontsource-variable/geist{,-mono}
  (stats/ declares its own)
- delete the committed draft renderer-performance plan doc
- turn on noUnusedLocals for typecheck and remove what it surfaced,
  including Windows focus-handoff values computed but never consumed

* docs(changes): add docs fragment and note retired hover messages

src/config/resolve/jellyfin.test.ts

@@ -97,9 +97,7 @@ test('anilist character dictionary fields are parsed, clamped, and enum-validate
   const { context, warnings } = createResolveContext({
     anilist: {
       characterDictionary: {
-        refreshTtlHours: 0,
         maxLoaded: 99,
-        evictionPolicy: 'purge' as never,
         profileScope: 'global' as never,
         collapsibleSections: {
           description: true,
@@ -112,9 +110,7 @@ test('anilist character dictionary fields are parsed, clamped, and enum-validate
 
   applyIntegrationConfig(context);
 
-  assert.equal(context.resolved.anilist.characterDictionary.refreshTtlHours, 1);
   assert.equal(context.resolved.anilist.characterDictionary.maxLoaded, 20);
-  assert.equal(context.resolved.anilist.characterDictionary.evictionPolicy, 'delete');
   assert.equal(context.resolved.anilist.characterDictionary.profileScope, 'all');
   assert.equal(context.resolved.anilist.characterDictionary.collapsibleSections.description, true);
   assert.equal(
@@ -124,9 +120,7 @@ test('anilist character dictionary fields are parsed, clamped, and enum-validate
   assert.equal(context.resolved.anilist.characterDictionary.collapsibleSections.voicedBy, true);
 
   const warnedPaths = warnings.map((warning) => warning.path);
-  assert.ok(warnedPaths.includes('anilist.characterDictionary.refreshTtlHours'));
   assert.ok(warnedPaths.includes('anilist.characterDictionary.maxLoaded'));
-  assert.ok(warnedPaths.includes('anilist.characterDictionary.evictionPolicy'));
   assert.ok(warnedPaths.includes('anilist.characterDictionary.profileScope'));
   assert.ok(
     warnedPaths.includes('anilist.characterDictionary.collapsibleSections.characterInformation'),
@@ -134,7 +128,7 @@ test('anilist character dictionary fields are parsed, clamped, and enum-validate
 });
 
 test('yomitan externalProfilePath is trimmed and invalid values warn', () => {
-  const { context, warnings } = createResolveContext({
+  const { context } = createResolveContext({
     yomitan: {
       externalProfilePath: '  /tmp/gsm-profile  ',
     },