fix(gitea-sync): survive live Gitea replies; point project memory at /buglog

gitea-sync.py fixes found on the first live run (bug-1855 follow-up):
- 204/empty-body replies (label DELETE) no longer crash in json.loads
- every request has a 60s timeout, so a stalled call fails instead of hanging
- spec.json sync state is inserted as a trailing "gitea" block instead of
  re-serializing the file (15 hand-formatted spec.json files would reflow)
- implementation issue body labels generated vs approved correctly; the
  validation body uses the same done-phase set as the close rules

Project memory now routes all buglog writes through the buglog skill:
CLAUDE.md key rule, a cerebrum Do-Not-Repeat entry (with the older
duplicate-id / json.dump / tags-vs-fix lessons tagged as superseded), and
xce-audit-invariants step 5.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

.claude/skills/xce-audit-invariants/SKILL.md

@@ -268,9 +268,12 @@ several minutes per mode.
 
 ## Step 5 — Record and report
 
-- Append every genuinely new root-caused bug to `.wolf/buglog.json` (id,
-  error_message, file, root_cause, fix, tags, related_bugs) — check the
-  existing entry count first so the new `bug-NNNN` id doesn't collide.
+- Log every genuinely new root-caused bug with the `buglog` skill:
+  `python3 scripts/buglog.py add --error ... --root-cause ... --file ...
+  --tags <component>,... --fix "<what changed>" --status fixed` (or `open` /
+  `partial` with `--note` for what remains). It assigns the id; don't pick one
+  by hand. For a violation that an existing entry already covers, update that
+  entry instead: `scripts/buglog.py status <id> ...` / `note <id> ...`.
 - Append durable, non-obvious learnings to `.wolf/cerebrum.md`'s Key
   Learnings section (anchor the edit near an existing dated entry to avoid
   the "## Key Learnings" heading collision — the file has one per dated