feat: diag_refs 對帳診斷 + ingest 進度可見性/Ctrl-C 安全 (Closes #2) (#5)

## 摘要

本 PR 含兩個獨立關注點,各一 commit。

### 1. `diag_refs` — source_ref↔manifest 對帳診斷 (`04f4fd5`) — 回應 #4

lint 的「source_ref 不在 manifest」只報對不上、不辨成因。新增 `tools/diag_refs.py`,把每個對不上的 source_ref 分成五類(hash 不符／路徑字串岔開／檔名 hash 後綴岔開／檔在磁碟未登記／完全無對應),各附修法,讓「補帳本(§14.3)」與「修規則(§12)」的相反處置不再混為一談。純唯讀、結束碼 `0/1`,可當搬機或改 manifest 後的閘門。附 selfcheck 驗五型別分類、結束碼與零寫檔。README §3.3/§6/§7/§8 同步。

### 2. ingest 進度可見性 + Ctrl-C 安全回復 (`4add7fa`) — Closes #2

`--all-pending` 長時間本地 Ollama 攝入全程靜默,使用者不確定有沒有在跑、又不敢中斷:

- **進度可見**:每份來源 `[i/N]`、長文件逐段 `分段 k/n`、每個 item `↳ 新增/更新`、完成 `✓`,全 `flush=True` 即時顯示。
- **Ctrl-C 安全**:獨立攔 `KeyboardInterrupt`(它不是 `Exception` 子類,原本會略過善後)。因 commit 在迴圈之後,**main 必然未受影響**;中斷時印可照做的回復指令並以結束碼 130 收場。

## 測試

- `python tools/selfcheck_diag_refs.py` — ALL PASS
- `python tools/selfcheck_ingest.py` — ALL PASS(含進度標記、中斷後 main 未動、回復指令實測可回乾淨 main)
- README markdownlint 0 issues

Closes #2

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: LittleYellow <crazytea@gmail.com>
Reviewed-on: #5

tools/selfcheck_ingest.py

@@ -5,11 +5,13 @@
 執行：.venv/Scripts/python tools/selfcheck_ingest.py
 """
 import hashlib
+import io
 import pathlib
 import shutil
 import subprocess
 import sys
 import tempfile
+from contextlib import redirect_stderr, redirect_stdout
 
 sys.path.insert(0, str(pathlib.Path(__file__).parent))
 import kb
@@ -82,9 +84,14 @@ def main():
         git(root, "add", "-A")
         git(root, "commit", "-q", "-m", "init")
 
-        # 1) 攝入：建分支、產頁、commit、回到 main
+        # 1) 攝入：建分支、產頁、commit、回到 main（並驗進度輸出可見，issue #2）
         kb.llm_json = fake_llm
-        ingest.main(["raw/converted/doc1.md", "--root", str(root)])
+        buf = io.StringIO()
+        with redirect_stdout(buf):
+            ingest.main(["raw/converted/doc1.md", "--root", str(root)])
+        out = buf.getvalue()
+        for marker in ("[1/1] 攝入", "分段 1/", "↳ 新增", "✓ ", "完成"):
+            assert marker in out, f"進度輸出缺少 {marker!r}\n{out}"
         assert git(root, "branch", "--show-current") == "main"
         branch = git(root, "branch", "--list", "ingest/*").strip("* ").strip()
         assert branch, "未建立 ingest 分支"
@@ -147,6 +154,45 @@ def main():
         except RuntimeError as e:
             assert "fallback" in str(e)
         print("PASS: 重試 + fallback 切換 + 全失敗報錯")
+
+        # 5) Ctrl-C 安全（issue #2）：中斷時 main 不受影響、以 130 收場，
+        #    且文件宣稱的回復指令真的能回到乾淨 main。第 2 份來源開始摘要時中斷，
+        #    此時第 1 份的頁面已寫入（未追蹤、未 commit）——正是使用者最怕的半成品狀態。
+        add_doc(root, "docA.md", "來源A：待攝入。")
+        add_doc(root, "docB.md", "來源B：待攝入。")
+        git(root, "add", "-A")
+        git(root, "commit", "-q", "-m", "docA/docB")
+        head_before = git(root, "rev-parse", "main")  # 攝入不得動到的 main 狀態
+        state = {"n": 0}
+        def boom(cfg, task, prompt, validate):
+            state["n"] += 1
+            if state["n"] >= 2:  # 第 2 份來源的 summarize 呼叫
+                raise KeyboardInterrupt
+            return ({"title": "來源A", "description": "d", "slug": "fresh-a",
+                     "tags": ["x"], "summary_markdown": "- a", "knowledge_items": []},
+                    "fake:test")
+        kb.llm_json = boom
+        err = io.StringIO()
+        try:
+            with redirect_stdout(io.StringIO()), redirect_stderr(err):
+                ingest.main(["raw/converted/docA.md", "raw/converted/docB.md",
+                             "--root", str(root)])
+            raise AssertionError("KeyboardInterrupt 應轉為 SystemExit(130)")
+        except SystemExit as e:
+            assert e.code == 130, e.code
+        msg = err.getvalue()
+        assert "git checkout main" in msg and "main 未受影響" in msg, msg
+        assert git(root, "rev-parse", "main") == head_before, "main 被動到了！"
+        cur = git(root, "branch", "--show-current")
+        assert cur.startswith("ingest/"), f"中斷後應停在 ingest 分支，實得 {cur!r}"
+        assert git(root, "status", "--porcelain"), "應有未提交的半成品"
+        # 照文件指令回復，斷言真的回到乾淨 main（驗「結果可用」，非「字串存在」，§13.4）
+        git(root, "checkout", "main")
+        git(root, "stash", "-u")
+        git(root, "branch", "-D", cur)
+        assert git(root, "branch", "--show-current") == "main"
+        assert not git(root, "status", "--porcelain"), "回復後工作區仍不乾淨"
+        print("PASS: Ctrl-C → main 未受影響、130 收場、回復指令實測可回乾淨 main")
         print("ALL PASS")
     finally:
         kb.llm_json, kb.ollama_chat = real_llm, real_chat