chore(台账): docfix 合并后回填体积同码凭证

合并提交 1b5b2f6b 让主干源码索引变了码，`/keil-build` 实测 0 错 0 警、
Program Size 逐项未变（Code=246720 RO=29836 RW=2052 ZI=149708，
RW_IRAM1 94,336 B / RW_CCM 57,376 B）——这笔合入只碰注释与文档，
体积数字与合并前一致，故只重写凭证、不新增趋势行。

- 工具：`task_worktree.py postmerge`（短链 `ram_baseline.py --update`）
- 复检：`check_size_gate.py --local` 绿（同码 ✓ 受管区 ≤92% ✓）
- 顺带：`check_doc_links.py --all` 全库绿（218 文档 / 3058 处章节引用 /
  机器可判定 81% / 失效 0）

scripts/size_attestation.json

@@ -1,15 +1,15 @@
 {
-  "built_at": "2026-10-30T13:37:20+08:00",
-  "fingerprint": "b3a7b7fb3c811de526c065a0dcb3a380d5fd0749f711433cfd167632f601e41a",
+  "built_at": "2026-10-30T14:26:00+08:00",
+  "fingerprint": "d1418d955270ec42439af3ed9e99e73870c7c1f5923d8500e0465002dd868ccf",
   "fingerprint_files": 1466,
   "fingerprint_source": "git-index",
   "gated_regions": [
     "RW_IRAM1",
     "RW_CCM"
   ],
-  "git_head": "3cce00a7cb945fe25dce9bea15280b7b26cff088",
+  "git_head": "1b5b2f6b7e3287eb0c9c9836f4fe23583ffb51f1",
   "map": "MDK-ARM/STM32F407-Demo/STM32F407-Demo.map",
-  "map_mtime": 1793338595,
+  "map_mtime": 1793341521,
   "pct": {
     "ER_IROM1": 26.37,
     "RW_CCM": 87.89,