feat: 添加 Provider Registry、StatusLine、Cache Stats 和其他增强

- providerRegistry: OpenAI 兼容 provider 切换（Cerebras/Groq/DeepSeek/Qwen）
- StatusLine: 增强状态栏（缓存命中率、TTL 倒计时、自定义 shell 命令）
- cacheStats: 缓存命中率和 token 签名追踪
- ultrareviewPreflight: 代码审查预检服务
- SkillsMenu/filterSkills: 技能菜单过滤增强
- MagicDocs/langfuse prompts: 提示词更新
- claude.ts: API 客户端更新

Co-Authored-By: glm-5-turbo <zai-org@claude-code-best.win>

src/utils/cacheStats.ts

@@ -0,0 +1,109 @@
+import { createHash } from 'node:crypto'
+import { mkdir, readFile, rename, writeFile } from 'node:fs/promises'
+import { dirname, join } from 'node:path'
+import { getClaudeConfigHomeDir } from './envUtils.js'
+
+// ---------------------------------------------------------------------------
+// Types
+// ---------------------------------------------------------------------------
+
+export interface CacheUsage {
+  input_tokens: number
+  cache_creation_input_tokens: number
+  cache_read_input_tokens: number
+}
+
+export interface CacheStatsState {
+  version: 1
+  signature: string | null
+  lastResetAt: number | null // ms epoch; reset when signature changes
+  lastHitRate: number | null // persisted fallback
+}
+
+// ---------------------------------------------------------------------------
+// Pure functions
+// ---------------------------------------------------------------------------
+
+/**
+ * Compute integer hit rate (0–100) or null if denominator is zero / input null.
+ */
+export function computeHitRate(u: CacheUsage | null): number | null {
+  if (!u) return null
+  const denom =
+    u.input_tokens + u.cache_creation_input_tokens + u.cache_read_input_tokens
+  if (denom === 0) return null
+  return Math.round((u.cache_read_input_tokens / denom) * 100)
+}
+
+/**
+ * Stable string that uniquely identifies a usage snapshot.
+ * A change in signature means a new API response arrived — reset the TTL clock.
+ */
+export function tokenSignature(u: CacheUsage): string {
+  return `${u.input_tokens}|${u.cache_creation_input_tokens}|${u.cache_read_input_tokens}`
+}
+
+// ---------------------------------------------------------------------------
+// State file I/O
+// ---------------------------------------------------------------------------
+
+/**
+ * Deterministic, short file name derived from sessionId so that:
+ *   - Different sessions never collide.
+ *   - The raw session id is never written to disk.
+ */
+export function getStateFilePath(sessionId: string): string {
+  const hash = createHash('sha256').update(sessionId).digest('hex').slice(0, 16)
+  return join(getClaudeConfigHomeDir(), 'cache-stats', `${hash}.json`)
+}
+
+const INIT_STATE: CacheStatsState = {
+  version: 1,
+  signature: null,
+  lastResetAt: null,
+  lastHitRate: null,
+}
+
+function isValidState(obj: unknown): obj is CacheStatsState {
+  if (typeof obj !== 'object' || obj === null) return false
+  const s = obj as Record<string, unknown>
+  return (
+    s['version'] === 1 &&
+    (s['signature'] === null || typeof s['signature'] === 'string') &&
+    (s['lastResetAt'] === null || typeof s['lastResetAt'] === 'number') &&
+    (s['lastHitRate'] === null || typeof s['lastHitRate'] === 'number')
+  )
+}
+
+/**
+ * Read state file. Returns init defaults on any error (corrupt, missing, etc.).
+ */
+export async function readState(filePath: string): Promise<CacheStatsState> {
+  try {
+    const raw = await readFile(filePath, 'utf8')
+    const parsed: unknown = JSON.parse(raw)
+    if (isValidState(parsed)) return parsed
+    return { ...INIT_STATE }
+  } catch {
+    return { ...INIT_STATE }
+  }
+}
+
+/**
+ * Write state atomically: write to a tmp file then rename — safe against
+ * partial-write corruption and concurrent reads.
+ */
+export async function writeStateAtomic(
+  filePath: string,
+  state: CacheStatsState,
+): Promise<void> {
+  const dir = dirname(filePath)
+  await mkdir(dir, { recursive: true })
+  const tmp = `${filePath}.${process.pid}.tmp`
+  try {
+    await writeFile(tmp, JSON.stringify(state), 'utf8')
+    await rename(tmp, filePath)
+  } catch {
+    // Best-effort; silently ignore errors so the UI never crashes
+  }
+}