perf: pre-compile regex patterns and optimize hot-path string operations

- error-classifier: pre-compile default retry pattern regex
- think-mode/detector: combine multilingual patterns into single regex
- parser: skip redundant toLowerCase on pre-lowered keywords
- edit-operations: use fast arraysEqual instead of JSON comparison
- hash-computation: optimize streaming line extraction with index tracking

src/hooks/runtime-fallback/error-classifier.ts

@@ -28,6 +28,8 @@ export function getErrorMessage(error: unknown): string {
   }
 }
 
+const DEFAULT_RETRY_PATTERN = new RegExp(`\\b(${DEFAULT_CONFIG.retry_on_errors.join("|")})\\b`)
+
 export function extractStatusCode(error: unknown, retryOnErrors?: number[]): number | undefined {
   if (!error) return undefined
 
@@ -45,8 +47,9 @@ export function extractStatusCode(error: unknown, retryOnErrors?: number[]): num
     return statusCode
   }
 
-  const codes = retryOnErrors ?? DEFAULT_CONFIG.retry_on_errors
-  const pattern = new RegExp(`\\b(${codes.join("|")})\\b`)
+  const pattern = retryOnErrors 
+    ? new RegExp(`\\b(${retryOnErrors.join("|")})\\b`)
+    : DEFAULT_RETRY_PATTERN
   const message = getErrorMessage(error)
   const statusMatch = message.match(pattern)
   if (statusMatch) {