feat(kaizen): parse tag/first_seen/age per signal

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

scripts/friction-scan.py

@@ -16,6 +16,9 @@ import re
 REPO_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 FRICTION = os.path.join(REPO_ROOT, "docs", "FRICTION.md")
 
+TAG_RE = re.compile(r"`\[(friction|gotcha|recurring|unused)\]`")
+DATE_RE = re.compile(r"(\d{4})-(\d{2})-(\d{2})")
+
 
 def extract_open_section(text):
     """Return the body between '## Open signals' and the next '## ' heading."""
@@ -59,5 +62,27 @@ def split_signals(section):
     return [s for s in signals if s]
 
 
+def parse_signal(raw, today):
+    """Turn one raw signal block into a structured dict."""
+    tag_m = TAG_RE.search(raw)
+    date_m = DATE_RE.search(raw)
+    if date_m:
+        first_seen = date_m.group(0)
+        seen = datetime.date(int(date_m.group(1)), int(date_m.group(2)), int(date_m.group(3)))
+        age_days = (today - seen).days
+    else:
+        first_seen = None
+        age_days = None
+    return {
+        "tag": tag_m.group(1) if tag_m else None,
+        "first_seen": first_seen,
+        "age_days": age_days,
+        "recurrence_count": 1,          # refined in Task 3
+        "referenced_paths": [],         # filled in Task 3
+        "still_exists": True,           # filled in Task 3
+        "text": " ".join(raw.split()),
+    }
+
+
 if __name__ == "__main__":  # pragma: no cover (filled in Task 4)
     pass

tests/test_friction_scan.py

@@ -38,3 +38,24 @@ def test_split_signals_finds_two_items_and_joins_continuations():
     assert len(signals) == 2
     assert "continuation line two" in signals[0]
     assert signals[1].startswith("`[friction]`")
+
+
+import datetime
+
+TODAY = datetime.date(2026, 6, 15)
+
+
+def test_parse_signal_extracts_tag_and_date_and_age():
+    raw = fs.split_signals(fs.extract_open_section(SAMPLE))[0]
+    sig = fs.parse_signal(raw, TODAY)
+    assert sig["tag"] == "gotcha"
+    assert sig["first_seen"] == "2026-06-01"
+    assert sig["age_days"] == 14
+    assert "First thing" in sig["text"]
+
+
+def test_parse_signal_handles_missing_date():
+    sig = fs.parse_signal("`[unused]` **No date here** something", TODAY)
+    assert sig["tag"] == "unused"
+    assert sig["first_seen"] is None
+    assert sig["age_days"] is None