refactor: remove dead file task-id-validator.ts and unused isModelAvailable from model-name-matcher

src/shared/model-name-matcher.ts

@@ -83,9 +83,3 @@ export function fuzzyMatchModel(
 	return result
 }
 
-export function isModelAvailable(
-	targetModel: string,
-	availableModels: Set<string>,
-): boolean {
-	return fuzzyMatchModel(targetModel, availableModels) !== null
-}

src/tools/task/task-id-validator.ts

@@ -1,6 +0,0 @@
-const TASK_ID_PATTERN = /^T-[A-Za-z0-9-]+$/
-
-export function parseTaskId(id: string): string | null {
-  if (!TASK_ID_PATTERN.test(id)) return null
-  return id
-}