feat(kaizen): friction-scan section extraction + signal split

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

scripts/friction-scan.py

@@ -0,0 +1,63 @@
+#!/usr/bin/env python3
+"""Parse docs/FRICTION.md 'Open signals' into structured data for /kaizen.
+
+Stdlib only. Modes:
+  --json  (default): emit the open signals as JSON (Phase-0 input for /kaizen)
+  --nudge          : print a one-line 'loop overdue?' summary
+
+Authoritative design: docs/superpowers/specs/2026-06-14-kaizen-command-design.md
+"""
+import argparse
+import datetime
+import json
+import os
+import re
+
+REPO_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+FRICTION = os.path.join(REPO_ROOT, "docs", "FRICTION.md")
+
+
+def extract_open_section(text):
+    """Return the body between '## Open signals' and the next '## ' heading."""
+    lines = text.splitlines()
+    start = None
+    for i, line in enumerate(lines):
+        if line.strip().lower() == "## open signals":
+            start = i + 1
+            break
+    if start is None:
+        return ""
+    end = len(lines)
+    for j in range(start, len(lines)):
+        if lines[j].startswith("## "):
+            end = j
+            break
+    return "\n".join(lines[start:end])
+
+
+def split_signals(section):
+    """Split the Open-signals body into raw per-signal blocks.
+
+    A signal starts with a top-level '- ' bullet; indented or blank lines are
+    continuations. Returns a list of multi-line strings with the leading '- '
+    stripped from the first line."""
+    signals = []
+    current = None
+    for line in section.splitlines():
+        if line.startswith("- "):
+            if current is not None:
+                signals.append("\n".join(current).strip())
+            current = [line[2:]]
+        elif current is not None:
+            if line.strip() == "" or line.startswith("  "):
+                current.append(line.strip())
+            else:
+                signals.append("\n".join(current).strip())
+                current = None
+    if current is not None:
+        signals.append("\n".join(current).strip())
+    return [s for s in signals if s]
+
+
+if __name__ == "__main__":  # pragma: no cover (filled in Task 4)
+    pass

tests/test_friction_scan.py

@@ -0,0 +1,40 @@
+import importlib.util
+import os
+
+_SPEC = importlib.util.spec_from_file_location(
+    "friction_scan",
+    os.path.join(os.path.dirname(__file__), "..", "scripts", "friction-scan.py"),
+)
+fs = importlib.util.module_from_spec(_SPEC)
+_SPEC.loader.exec_module(fs)
+
+SAMPLE = """# FRICTION.md
+
+## Open signals
+
+_(append new raw signals here)_
+
+- `[gotcha]` **First thing** (2026-06-01): body line one.
+  continuation line two.
+- `[friction]` **Second thing** (2026-06-10): only one line.
+
+---
+
+## Kaizen reviews — decisions ledger
+
+- `[gotcha]` **Should not be parsed** (2026-01-01): in the ledger.
+"""
+
+
+def test_extract_open_section_stops_at_next_heading():
+    section = fs.extract_open_section(SAMPLE)
+    assert "First thing" in section
+    assert "Second thing" in section
+    assert "Should not be parsed" not in section
+
+
+def test_split_signals_finds_two_items_and_joins_continuations():
+    signals = fs.split_signals(fs.extract_open_section(SAMPLE))
+    assert len(signals) == 2
+    assert "continuation line two" in signals[0]
+    assert signals[1].startswith("`[friction]`")