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/messages.lua

@@ -4,7 +4,6 @@ function M.create(ctx)
 	local mp = ctx.mp
 	local opts = ctx.opts
 	local process = ctx.process
-	local hover = ctx.hover
 	local ui = ctx.ui
 	local state = ctx.state
 
@@ -49,12 +48,6 @@ function M.create(ctx)
 		mp.register_script_message("subminer-overlay-loading-ready", function()
 			process.stop_overlay_loading_osd()
 		end)
-		mp.register_script_message(hover.HOVER_MESSAGE_NAME, function(payload_json)
-			hover.handle_hover_message(payload_json)
-		end)
-		mp.register_script_message(hover.HOVER_MESSAGE_NAME_LEGACY, function(payload_json)
-			hover.handle_hover_message(payload_json)
-		end)
 		mp.register_script_message("subminer-stats-toggle", function()
 			if opts.osd_messages then
 				mp.osd_message("Stats: press ` (backtick) in overlay", 3)