feat(cli): stats subcommand + rebuild_index busy signal (v0.13.0)

Three changes driven by real-usage-data review of this repo's
own `.code-graph/usage.jsonl`:

1. `code-graph-mcp stats` — new CLI subcommand that aggregates
   JSONL session metrics (per-tool counts, search totals, index
   activity). Running on this repo's 153-session, 570-call history
   surfaced the rebuild_index error pattern motivating change #2.
   Flags: `--last N`, `--json`. 5 new unit tests on the pure
   `aggregate_usage_jsonl` helper.

2. `rebuild_index` MCP tool: embedding-busy rejection now returns
   `Ok({status:"busy", retry_after_ms:2000})` instead of `Err`,
   matching `run_incremental_with_cache_restore`'s precedent and
   keeping the usage-metrics `err` counter from inflating on
   legitimate retry signals. **Contract change** — SDK clients
   must now distinguish busy success payloads from JSON-RPC errors;
   JSON-RPC errors on this tool now indicate real failures only.

3. `plugin_code_graph_mcp.md` template: CLI `search` (FTS5-only)
   and MCP `semantic_code_search` (RRF hybrid of FTS5 + vector)
   are no longer conflated — the core-7 decision table and CLI
   cheat sheet now state the difference explicitly. Adopted
   memory files auto-refresh on next SessionStart (v0.11.0+).

Clippy 1.95 parity verified pre-push:
`cargo +1.95.0 clippy --no-default-features -- -D warnings` ✓
`cargo +1.95.0 clippy --all-targets -- -D warnings`          ✓

235/235 lib tests pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: sdsrss

.claude-plugin/marketplace.json

@@ -5,14 +5,14 @@
   },
   "metadata": {
     "description": "AST knowledge graph plugin for Claude Code — semantic search, call graph, HTTP tracing, impact analysis",
-    "version": "0.12.1"
+    "version": "0.13.0"
   },
   "plugins": [
     {
       "name": "code-graph-mcp",
       "source": "./claude-plugin",
       "description": "AST knowledge graph for intelligent code navigation — auto-indexes your codebase and provides semantic search, call graph traversal, HTTP route tracing, and impact analysis via MCP tools",
-      "version": "0.12.1",
+      "version": "0.13.0",
       "author": {
         "name": "sdsrs"
       },

CHANGELOG.md

@@ -1,5 +1,55 @@
 # Changelog
 
+## v0.13.0 — `stats` CLI + rebuild_index busy semantics + CLI/MCP search disambiguation
+
+Minor release. Three changes driven by real-usage-data review:
+
+### `stats` subcommand (new)
+
+`code-graph-mcp stats` aggregates `.code-graph/usage.jsonl` across sessions
+and prints per-tool counts (`n`, `avg_ms`, `err`, `max_ms`), search totals
+(queries, zero-result ratio, hybrid/FTS split, avg quality), and index
+activity (full vs incremental, avg full-rebuild time). Flags: `--last N`
+limits to the most recent N sessions, `--json` emits structured output.
+
+Motivation: the metrics module has been writing JSONL for months (1MB
+rotation), but there was no reader. Running on this repo's own history
+surfaced the `rebuild_index` error pattern that motivates change #2.
+
+### `rebuild_index` MCP tool — busy signal is no longer an error
+
+When the server rejects a rebuild request because background embedding is
+still running, it now returns `Ok({status: "busy", retry_after_ms: 2000})`
+instead of `Err("Background embedding still in progress")`. This matches
+the precedent in `run_incremental_with_cache_restore` (which returns
+`Ok(())` on the same condition) and keeps the usage-metrics `err` counter
+from inflating on legitimate retry signals.
+
+**Contract change** — SDK/script clients of the `rebuild_index` MCP tool
+must now distinguish `status: "busy"` success payloads from actual errors.
+JSON-RPC-level errors on `rebuild_index` now indicate real failures only
+(missing `confirm`, no project root, DB error).
+
+### CLI ↔ MCP search disambiguation
+
+`plugin_code_graph_mcp.md` template previously listed `search "Z"` and
+`semantic_code_search` as equivalent intents. They are not: the CLI
+`search` command is **FTS5-only** (`src/cli.rs:710` → `fts5_search`), while
+the MCP `semantic_code_search` tool performs **RRF fusion** of FTS5 + vector
+similarity (`src/mcp/server/tools.rs:42 → 101`). The template now states
+this explicitly in the core-7 decision table and the CLI cheat sheet.
+
+Adopted memory files auto-refresh from the template on the next
+SessionStart (v0.11.0+ behavior).
+
+### Clippy 1.95 parity
+
+Four `clippy::manual_checked_ops` and one `clippy::unnecessary_sort_by`
+flagged by the 1.95 toolchain in the new `cmd_stats` code path are fixed
+before push (local baseline: `cargo +1.95.0 clippy --no-default-features
+-- -D warnings && cargo +1.95.0 clippy --all-targets -- -D warnings`,
+both green).
+
 ## v0.12.1 — incremental-index skips non-project directories
 
 Bugfix release: the PostToolUse `incremental-index` hook no longer creates

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "code-graph-mcp"
-version = "0.12.1"
+version = "0.13.0"
 edition = "2021"
 
 [features]

Cargo.toml

@@ -4,7 +4,7 @@
   "author": {
     "name": "sdsrs"
   },
-  "version": "0.12.1",
+  "version": "0.13.0",
   "keywords": [
     "code-graph",
     "ast",

claude-plugin/.claude-plugin/plugin.json

@@ -30,7 +30,7 @@ type: reference
 |------|------|----------------|
 | "谁调用 X？" / "X 调了啥？" | `get_call_graph` / `callgraph X` | 替代 `grep "X("` |
 | "Y 模块长啥样？" | `module_overview` / `overview Y/` | 替代逐文件 Read |
-| "找做 Z 的代码"（概念） | `semantic_code_search` / `search "Z"` | 不知道精确名 |
+| "找做 Z 的代码"（概念） | MCP `semantic_code_search`（RRF 混合）；CLI `search`（纯 FTS5） | 不知道精确名；要向量召回走 MCP |
 | "返回 T 类型的函数" | `ast_search --returns T` | 结构化筛选 |
 | "X 在哪被引用？" | `find_references` / `refs X` | 含 callers/importers |
 | "看 X 的源码 / 签名" | `get_ast_node` / `show X` | `include_impact=true` 含影响面（替代 impact_analysis） |
@@ -76,7 +76,7 @@ type: reference
 
 ```
 code-graph-mcp grep "pattern" [path]     # ripgrep + AST 上下文
-code-graph-mcp search "concept"          # FTS5 语义搜索
+code-graph-mcp search "concept"          # 纯 FTS5（要混合检索走 MCP semantic_code_search）
 code-graph-mcp ast-search "q" --type fn  # 结构化筛选
 code-graph-mcp map                       # 项目架构
 code-graph-mcp overview src/mcp/         # 模块总览

claude-plugin/templates/plugin_code_graph_mcp.md

@@ -1,6 +1,6 @@
 {
   "name": "@sdsrs/code-graph-darwin-arm64",
-  "version": "0.12.1",
+  "version": "0.13.0",
   "description": "code-graph-mcp binary for macOS ARM64",
   "license": "MIT",
   "repository": {

npm/darwin-arm64/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@sdsrs/code-graph-darwin-x64",
-  "version": "0.12.1",
+  "version": "0.13.0",
   "description": "code-graph-mcp binary for macOS x64",
   "license": "MIT",
   "repository": {

npm/darwin-x64/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@sdsrs/code-graph-linux-arm64",
-  "version": "0.12.1",
+  "version": "0.13.0",
   "description": "code-graph-mcp binary for Linux ARM64",
   "license": "MIT",
   "repository": {

npm/linux-arm64/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@sdsrs/code-graph-linux-x64",
-  "version": "0.12.1",
+  "version": "0.13.0",
   "description": "code-graph-mcp binary for Linux x64",
   "license": "MIT",
   "repository": {