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/types/config.ts

@@ -4,7 +4,6 @@ import type {
   AiConfig,
   AiFeatureConfig,
   AnilistCharacterDictionaryCollapsibleSectionsConfig,
-  AnilistCharacterDictionaryEvictionPolicy,
   AnilistCharacterDictionaryProfileScope,
   AnilistConfig,
   DiscordPresenceConfig,
@@ -345,9 +344,7 @@ export interface ResolvedConfig {
     enabled: boolean;
     accessToken: string;
     characterDictionary: {
-      refreshTtlHours: number;
       maxLoaded: number;
-      evictionPolicy: AnilistCharacterDictionaryEvictionPolicy;
       profileScope: AnilistCharacterDictionaryProfileScope;
       collapsibleSections: Required<AnilistCharacterDictionaryCollapsibleSectionsConfig>;
     };