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

plugin/subminer/bootstrap.lua

@@ -56,9 +56,6 @@ function M.init()
 	ctx.binary = make_lazy_proxy("binary", function()
 		return require("binary").create(ctx)
 	end)
-	ctx.hover = make_lazy_proxy("hover", function()
-		return require("hover").create(ctx)
-	end)
 	ctx.process = make_lazy_proxy("process", function()
 		return require("process").create(ctx)
 	end)