W15: conflict resolution — E7 CRITICAL gate, T11/T18 audit refs, §5 metadata check, PROMPT_TEMPLATE Fixes (W15.4-W15.9)

- W15.4 (杨帆): §11/§14 cross-reference audit — PASS-WITH-NOTES, 3 fixes needed
- W15.5 (王测): §14 internal consistency — PASS-WITH-NOTES, 4 fixes needed
- W15.6 (胡桐): self-check script + YAML verification — PASS
- W15.7 (杨帆): Add E7 (no OPEN CRITICAL) to EXPRESS conditions, update T11 to include §14.4 A1-A4, add T18 finding status in §14.5
- W15.8 (王测): Fix findings-registry Close Date, add historical finding time-limit rule, add legacy audit Findings Summary note, add Fixes annotation to PROMPT_TEMPLATE
- W15.9 (胡桐): Fix false-positive warning in check_agents_metadata.py (skip audits/ dir), add metadata check to §5

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

agents/audits/findings-registry.md

@@ -25,7 +25,9 @@
 
 ## Closed Findings
 
-| ID | Severity | Source | Title | Closed Date | Fix Wave | Verified By |
+> Closed Findings 表必须包含 Close Date 字段（格式 YYYY-MM-DD），记录发现关闭日期。字段定义见 WORKFLOW.md §14.1。
+
+| ID | Severity | Source | Title | Close Date | Fix Wave | Verified By |
 |----|----------|--------|-------|-------------|----------|-------------|
 | — | — | — | 暂无已关闭发现 | — | — | — |