fix: auto-detect issue number in cycle retro from git branch (#495)

## Summary
- `cycle_retro.py` now auto-detects issue number from the git branch name (e.g. `kimi/issue-492` → `492`) when `--issue` is not provided
- `backfill_retro.py` now skips the PR number suffix Gitea appends to titles so it does not confuse PR numbers with issue numbers
- Added tests for both fixes

Fixes #492

Co-authored-by: kimi <kimi@localhost>
Reviewed-on: http://localhost:3000/rockachopa/Timmy-time-dashboard/pulls/495
Co-authored-by: Kimi Agent <kimi@timmy.local>
Co-committed-by: Kimi Agent <kimi@timmy.local>

scripts/backfill_retro.py

@@ -94,12 +94,17 @@ def extract_cycle_number(title: str) -> int | None:
     return int(m.group(1)) if m else None
 
 
-def extract_issue_number(title: str, body: str) -> int | None:
-    # Try body first (usually has "closes #N")
+def extract_issue_number(title: str, body: str, pr_number: int | None = None) -> int | None:
+    """Extract the issue number from PR body/title, ignoring the PR number itself.
+
+    Gitea appends "(#N)" to PR titles where N is the PR number — skip that
+    so we don't confuse it with the linked issue.
+    """
     for text in [body or "", title]:
-        m = ISSUE_RE.search(text)
-        if m:
-            return int(m.group(1))
+        for m in ISSUE_RE.finditer(text):
+            num = int(m.group(1))
+            if num != pr_number:
+                return num
     return None
 
 
@@ -140,7 +145,7 @@ def main():
         else:
             cycle_counter = max(cycle_counter, cycle)
 
-        issue = extract_issue_number(title, body)
+        issue = extract_issue_number(title, body, pr_number=pr_num)
         issue_type = classify_pr(title, body)
         duration = estimate_duration(pr)
         diff = get_pr_diff_stats(token, pr_num)

scripts/cycle_retro.py

@@ -44,6 +44,8 @@ from __future__ import annotations
 
 import argparse
 import json
+import re
+import subprocess
 import sys
 from datetime import datetime, timezone
 from pathlib import Path
@@ -56,6 +58,23 @@ EPOCH_COUNTER_FILE = REPO_ROOT / ".loop" / "retro" / ".epoch_counter"
 # How many recent entries to include in rolling summary
 SUMMARY_WINDOW = 50
 
+# Branch patterns that encode an issue number, e.g. kimi/issue-492
+BRANCH_ISSUE_RE = re.compile(r"issue[/-](\d+)", re.IGNORECASE)
+
+
+def detect_issue_from_branch() -> int | None:
+    """Try to extract an issue number from the current git branch name."""
+    try:
+        branch = subprocess.check_output(
+            ["git", "rev-parse", "--abbrev-ref", "HEAD"],
+            stderr=subprocess.DEVNULL,
+            text=True,
+        ).strip()
+    except (subprocess.CalledProcessError, FileNotFoundError):
+        return None
+    m = BRANCH_ISSUE_RE.search(branch)
+    return int(m.group(1)) if m else None
+
 
 # ── Epoch turnover ────────────────────────────────────────────────────────
 
@@ -230,6 +249,10 @@ def update_summary() -> None:
 def main() -> None:
     args = parse_args()
 
+    # Auto-detect issue from branch when not explicitly provided
+    if args.issue is None:
+        args.issue = detect_issue_from_branch()
+
     # Reject idle cycles — no issue and no duration means nothing happened
     if not args.issue and args.duration == 0:
         print(f"[retro] Cycle {args.cycle} skipped — idle (no issue, no duration)")