refactor: codebase cleanup — dead code, regex helper, centralized constants, tests

- Remove unused validateTokenCounts/validateTokensAndCost exports and PlanPhase type alias
- Add execPattern() helper to eliminate 8 repetitive .lastIndex=0 + exec() loops
- Centralize 11 magic number constants into config/ai-defaults.ts and config/server-timing.ts
- Remove stale src/tui from tsconfig.json exclude
- Fix CLAUDE.md inaccuracies (session helpers, app.js line count, module count)
- Add 316 new tests: LRUMap (38), StaleExpirationMap (42), BufferAccumulator (33),
  respawn helpers (142), system-routes expansion (11→61)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/utils/index.ts

@@ -20,8 +20,9 @@ export {
   createAnsiPatternSimple,
   stripAnsi,
   SAFE_PATH_PATTERN,
+  execPattern,
 } from './regex-patterns.js';
-export { MAX_SESSION_TOKENS, validateTokenCounts, validateTokensAndCost } from './token-validation.js';
+export { MAX_SESSION_TOKENS } from './token-validation.js';
 export { stringSimilarity, fuzzyPhraseMatch, todoContentHash } from './string-similarity.js';
 export { assertNever } from './type-safety.js';
 export { wrapWithNice } from './nice-wrapper.js';

src/utils/regex-patterns.ts

@@ -79,3 +79,15 @@ export function stripAnsi(text: string): string {
 export const SPINNER_PATTERN = /[⠋⠙⠹⠸⠼⠴⠦⠧]/;
 
 export const SAFE_PATH_PATTERN = /^[a-zA-Z0-9_/\-. ~]+$/;
+
+/**
+ * Execute a global regex pattern against data, calling the callback for each match.
+ * Automatically resets lastIndex before execution.
+ */
+export function execPattern(pattern: RegExp, data: string, callback: (match: RegExpExecArray) => void): void {
+  pattern.lastIndex = 0;
+  let match: RegExpExecArray | null;
+  while ((match = pattern.exec(data)) !== null) {
+    callback(match);
+  }
+}

src/utils/token-validation.ts

@@ -1,7 +1,6 @@
 /**
- * @fileoverview Token validation utilities.
+ * @fileoverview Token validation constants.
  *
- * Centralizes token count validation logic used across the codebase.
  * Claude's context window is ~200k tokens, so 500k is a generous upper bound.
  *
  * @module utils/token-validation
@@ -12,58 +11,3 @@
  * Claude's context is ~200k, so 500k is a safe upper bound for validation.
  */
 export const MAX_SESSION_TOKENS = 500_000;
-
-/**
- * Validates token counts are within acceptable bounds.
- * Rejects negative values and values exceeding MAX_SESSION_TOKENS.
- *
- * @param inputTokens - Input token count to validate
- * @param outputTokens - Output token count to validate
- * @returns Object with isValid flag and optional error reason
- */
-export function validateTokenCounts(inputTokens: number, outputTokens: number): { isValid: boolean; reason?: string } {
-  if (inputTokens < 0 || outputTokens < 0) {
-    return {
-      isValid: false,
-      reason: `Negative token values: input=${inputTokens}, output=${outputTokens}`,
-    };
-  }
-
-  if (inputTokens > MAX_SESSION_TOKENS || outputTokens > MAX_SESSION_TOKENS) {
-    return {
-      isValid: false,
-      reason: `Token values exceed maximum (${MAX_SESSION_TOKENS}): input=${inputTokens}, output=${outputTokens}`,
-    };
-  }
-
-  return { isValid: true };
-}
-
-/**
- * Validates token counts and cost for restoration/persistence.
- * Returns true if all values are valid.
- *
- * @param inputTokens - Input token count
- * @param outputTokens - Output token count
- * @param cost - Cost value (must be non-negative)
- * @returns Object with isValid flag and optional error reason
- */
-export function validateTokensAndCost(
-  inputTokens: number,
-  outputTokens: number,
-  cost: number
-): { isValid: boolean; reason?: string } {
-  const tokenValidation = validateTokenCounts(inputTokens, outputTokens);
-  if (!tokenValidation.isValid) {
-    return tokenValidation;
-  }
-
-  if (cost < 0) {
-    return {
-      isValid: false,
-      reason: `Negative cost value: ${cost}`,
-    };
-  }
-
-  return { isValid: true };
-}