perf(shared): optimize hot-path utilities across plugin

- task-list: replace O(n³) blocker resolution with Map lookup (C4)
- logger: buffer log entries and flush periodically to reduce sync I/O (C5)
- plugin-interface: create chatParamsHandler once at init (H3)
- pattern-matcher: cache compiled RegExp for wildcard matchers (H6)
- file-reference-resolver: use replaceAll instead of split/join (M9)
- connected-providers-cache: add in-memory cache for read operations (L4)

src/shared/file-reference-resolver.ts

@@ -74,7 +74,7 @@ export async function resolveFileReferencesInText(
 
   let resolved = text
   for (const [pattern, replacement] of replacements.entries()) {
-    resolved = resolved.split(pattern).join(replacement)
+    resolved = resolved.replaceAll(pattern, replacement)
   }
 
   if (findFileReferences(resolved).length > 0 && depth + 1 < maxDepth) {