perf(comment-checker): add LSP-style background language warming

- Warmup common languages (python, typescript, javascript, tsx, go, rust, java) on plugin init
- Non-blocking background initialization using Promise.then() pattern
- First parse call uses pre-cached language - zero user wait time
- Refactor parser manager with ManagedLanguage interface for better state tracking

src/hooks/comment-checker/index.ts

@@ -1,5 +1,5 @@
 import type { PendingCall, FileComments } from "./types"
-import { detectComments, isSupportedFile } from "./detector"
+import { detectComments, isSupportedFile, warmupCommonLanguages } from "./detector"
 import { applyFilters } from "./filters"
 import { formatHookMessage } from "./output"
 
@@ -32,6 +32,9 @@ setInterval(cleanupOldPendingCalls, 10_000)
 export function createCommentCheckerHooks() {
   debugLog("createCommentCheckerHooks called")
   
+  // Background warmup - LSP style (non-blocking)
+  warmupCommonLanguages()
+  
   return {
     "tool.execute.before": async (
       input: { tool: string; sessionID: string; callID: string },