fix(orchestrator): persist spec_path on spec-phase pass (ADR-004)

Spec-refiner writes data_dir/specs/<project>/<story>.spec.md and returns
the path in verdict feedback, but cycle.py:set_phase() never copied it
onto the row. Build phase worked only because _find_spec_file fallback
used the same slug convention by luck.

- Add 3-line branch in cycle.py Txn 3: when verdict=pass and phase=spec,
  copy verdict_feedback["spec_path"] into extra_fields.
- Add tests/test_spec_path_persistence.py with two AC tests:
  test_pass_verdict_persists_spec_path, test_non_pass_verdict_does_not_persist.
- Defense-in-depth fallback (_find_spec_file) remains unchanged.

Refs: wiki/decisions/ADR-004-persist-spec-path-on-pass.md
Refs: wiki/decisions/research/adr-004-spec-path-research.md
Story: S1-persist-spec-path-on-spec-pass

src/damascus/cycle.py

@@ -128,6 +128,12 @@ def tick() -> dict:
                 extra_fields["branch"] = verdict_feedback["branch"]
             if "commit" in verdict_feedback:
                 extra_fields["base_commit"] = verdict_feedback["commit"]
+        # ADR-004: persist spec_path on spec-phase pass so build/review/dashboard
+        # can read it from the row instead of hitting disk every time. Schema
+        # already has the column; _find_spec_file fallback remains defense-in-depth.
+        if result["verdict"] == "pass" and item["phase"] == "spec":
+            if "spec_path" in verdict_feedback:
+                extra_fields["spec_path"] = verdict_feedback["spec_path"]
 
         # Amendment §4: `spec_ambiguous` does NOT consume the autonomous budget.
         # The claim already incremented attempts; roll it back so a human-blocked

tests/test_spec_path_persistence.py

@@ -0,0 +1,86 @@
+"""
+Unit tests for ADR-004: persist `spec_path` on spec-phase pass.
+
+Story: S1 — Persist spec_path on spec-phase pass
+ADR:    wiki/decisions/ADR-004-persist-spec-path-on-pass.md
+
+Contract:
+  - verdict=pass + phase=spec  => spec_path from feedback is written to the row.
+  - verdict != pass + phase=spec => spec_path is unchanged.
+
+These tests drive `cycle.tick()` against the real test Postgres (conftest's
+default `db-test` service) and stub `phases.refine_spec` so the LLM is
+never called. The other moveable parts (wiki, relay) are also stubbed so
+the test is hermetic.
+"""
+from __future__ import annotations
+
+import pytest
+
+from conftest import get_row, insert_work_item
+from damascus import cycle, phases, relay, wiki
+
+
+def _stub_phase_returning(verdict: str, feedback: dict):
+    """Build a fake phases.refine_spec that returns a fixed verdict/feedback."""
+    def fake_refine_spec(cur, item):
+        print(f"DEBUG stub: item phase={item.get('phase')!r} id={item.get('id')!r}")
+        print(f"DEBUG stub: returning verdict={verdict!r} feedback={feedback!r}")
+        return {"verdict": verdict, "feedback": feedback}
+    return fake_refine_spec
+
+
+def _run_tick_with_stub(monkeypatch, verdict: str, feedback: dict) -> None:
+    """Run one orchestrator tick with the spec phase stubbed.
+
+    wiki.init_wiki and relay.post are no-ops so the test does not touch
+    the host filesystem or any external service.
+    """
+    monkeypatch.setattr(wiki, "init_wiki", lambda: None)
+    monkeypatch.setattr(relay, "post", lambda line: None)
+    monkeypatch.setattr(phases, "refine_spec", _stub_phase_returning(verdict, feedback))
+
+    out = cycle.tick()
+    print(f"DEBUG tick: claimed={out['claimed']!r} transition={out['transition']!r}")
+    assert out["claimed"] is not None, "tick did not claim a row"
+    assert out["transition"]["verdict"] == verdict
+
+
+def test_pass_verdict_persists_spec_path(monkeypatch):
+    """AC: On verdict=pass in spec phase, work_items.spec_path equals
+    the absolute path returned in verdict_feedback."""
+    rid = insert_work_item(phase="spec", story_id="S1-pass", title="Persist spec path on pass")
+    expected_path = "/data/specs/wh40k-pc/S1-pass.spec.md"
+
+    _run_tick_with_stub(monkeypatch, "pass", {
+        "spec_path": expected_path,
+        "preview": "# Goal\n...",
+    })
+
+    row = get_row(rid)
+    assert row["spec_path"] == expected_path, (
+        f"spec_path not persisted on pass: row has {row['spec_path']!r}, "
+        f"expected {expected_path!r}"
+    )
+    # The phase should have advanced spec -> build (the contract for pass).
+    assert row["phase"] == "build"
+
+
+def test_non_pass_verdict_does_not_persist(monkeypatch):
+    """AC: On a non-pass verdict in spec phase, work_items.spec_path is unchanged.
+    For a freshly-inserted row, spec_path starts NULL and stays NULL."""
+    rid = insert_work_item(phase="spec", story_id="S1-nopass",
+                           title="Spec ambiguous case")
+
+    _run_tick_with_stub(monkeypatch, "spec_ambiguous", {
+        "issue_id": "test-issue-id",
+        "preview": "# Goal\n...",
+    })
+
+    row = get_row(rid)
+    assert row["spec_path"] is None, (
+        f"spec_path must be unchanged on non-pass; row has {row['spec_path']!r}"
+    )
+    # spec_ambiguous rolls back the attempts increment AND routes to
+    # awaiting_human (contract per ADR-004 + design doc §5).
+    assert row["phase"] == "awaiting_human"