fix(gateway): evidence/QA/doc paths populate files_changed from git

Bug:
    ContentActions.evidence() hard-coded files_changed=[] and diffed
    against HEAD~1 instead of the branch's parent. QA's _build_qa_claim_
    evidence (and doc/_impl mirrors) sourced files_changed from
    work_session.files_modified, which the gateway commit() never
    populates (no add_files_modified plumbing). Result: QA / docs / PM
    reviewers saw an empty change list on real PRs and only the latest
    commit's delta — flagged in smoke-9 when PR #20 showed the README
    change on GitHub but evidence() reported empty.

Fix:
    Added GitService.list_changed_files (git diff --name-only against
    parent branch). evidence(), _build_qa_claim_evidence,
    _claim_doc_evidence, and _build_i_am_done_ok all source files_changed
    from this — git is the authoritative source. evidence() also drops
    the HEAD~1 base so the diff is the full PR.

    Wired EvidenceRepo into ContentActionsDeps so evidence() returns
    journal_highlights too, matching the QA/doc shape.

tests/integration/test_full_lifecycle_real_db.py

@@ -119,6 +119,12 @@ class _StubGit:
         del branch_name, base, actor_agent_id
         return "stub diff"
 
+    async def list_changed_files(
+        self, *, branch_name: str, base: Any = None, actor_agent_id: Any = None
+    ) -> list[str]:
+        del branch_name, base, actor_agent_id
+        return []
+
     async def pr_target(self, pr_number: int, *, actor_agent_id: Any = None) -> str:
         del pr_number, actor_agent_id
         return "main"

tests/integration/test_lifecycle_real_db.py

@@ -121,6 +121,12 @@ class _StubGit:
         del branch_name, base, actor_agent_id
         return "stub diff"
 
+    async def list_changed_files(
+        self, *, branch_name: str, base: Any = None, actor_agent_id: Any = None
+    ) -> list[str]:
+        del branch_name, base, actor_agent_id
+        return []
+
     async def pr_target(self, pr_number: int, *, actor_agent_id: Any = None) -> str:
         del pr_number, actor_agent_id
         return "main"

tests/unit/gateway/test_choreographer_doc.py

@@ -70,9 +70,9 @@ async def test_claim_doc_task_returns_evidence() -> None:
     task_svc.list_paused_for_agent.return_value = []
     task_svc.doc_claim.return_value = after
     work_svc = AsyncMock()
-    work_svc.files_changed.return_value = ["README.md"]
     git_svc = AsyncMock()
     git_svc.diff.return_value = "+++ diff"
+    git_svc.list_changed_files.return_value = ["README.md"]
     deps = _make_deps(task=task_svc, work_session=work_svc, git=git_svc)
     c = Choreographer(deps)
 

tests/unit/gateway/test_choreographer_qa.py

@@ -78,9 +78,9 @@ async def test_claim_review_returns_evidence_inline() -> None:
     task_svc.list_paused_for_agent.return_value = []
     task_svc.qa_claim.return_value = t_claimed
     work_svc = AsyncMock()
-    work_svc.files_changed.return_value = ["README.md"]
     git_svc = AsyncMock()
     git_svc.diff.return_value = "+++ diff content"
+    git_svc.list_changed_files.return_value = ["README.md"]
     deps = _make_deps(task=task_svc, work_session=work_svc, git=git_svc)
     c = Choreographer(deps)
 

tests/unit/gateway/test_content_actions.py

@@ -37,6 +37,11 @@ def _make_deps(**overrides: AsyncMock) -> ContentActionsDeps:
     workspace = overrides.get("workspace", AsyncMock())
     notifications = overrides.get("notifications", AsyncMock())
     notification_delivery = overrides.get("notification_delivery", AsyncMock())
+    if "evidence_repo" in overrides:
+        evidence_repo = overrides["evidence_repo"]
+    else:
+        evidence_repo = AsyncMock()
+        evidence_repo.journal_highlights_for_task.return_value = []
     return ContentActionsDeps(
         task=task,
         git=git,
@@ -46,6 +51,7 @@ def _make_deps(**overrides: AsyncMock) -> ContentActionsDeps:
         workspace=workspace,
         notifications=notifications,
         notification_delivery=notification_delivery,
+        evidence_repo=evidence_repo,
     )
 
 

tests/unit/gateway/test_content_actions_ownership.py

@@ -44,6 +44,11 @@ def _make_deps(**overrides: AsyncMock) -> ContentActionsDeps:
     journal = overrides.get("journal", AsyncMock())
     workspace = overrides.get("workspace", AsyncMock())
     notifications = overrides.get("notifications", AsyncMock())
+    if "evidence_repo" in overrides:
+        evidence_repo = overrides["evidence_repo"]
+    else:
+        evidence_repo = AsyncMock()
+        evidence_repo.journal_highlights_for_task.return_value = []
     return ContentActionsDeps(
         task=task,
         git=git,
@@ -52,6 +57,7 @@ def _make_deps(**overrides: AsyncMock) -> ContentActionsDeps:
         journal=journal,
         workspace=workspace,
         notifications=notifications,
+        evidence_repo=evidence_repo,
     )
 
 

tests/unit/gateway/test_evidence_populates_files_changed.py

@@ -0,0 +1,182 @@
+"""Task #154: evidence() must populate files_changed + use full PR diff.
+
+Bug:
+    ContentActions.evidence() hard-coded ``files_changed=[]`` and called
+    ``git.diff(branch_name=..., base="HEAD~1")``. Result: QA / reviewers
+    inspecting a real PR saw an empty change list and only the latest
+    commit's delta, even when GitHub showed a multi-commit change set.
+
+Fix:
+    Pull files via ``git.list_changed_files(branch_name=...)`` (no base
+    → full diff vs parent branch). Pull diff with ``base=None`` so the
+    full PR diff comes through. Both use git as the authoritative source
+    instead of the legacy ``work_session.files_modified`` field, which
+    the gateway ``commit()`` does not populate.
+"""
+
+from __future__ import annotations
+
+from unittest.mock import AsyncMock, MagicMock
+from uuid import uuid4
+
+import pytest
+from roboco.services.gateway.content_actions import ContentActions, ContentActionsDeps
+
+
+def _deps_for_evidence(
+    task_svc: AsyncMock,
+    git_svc: AsyncMock,
+    workspace_svc: AsyncMock,
+    evidence_repo: AsyncMock,
+) -> ContentActionsDeps:
+    return ContentActionsDeps(
+        task=task_svc,
+        git=git_svc,
+        messaging=AsyncMock(),
+        a2a=AsyncMock(),
+        journal=AsyncMock(),
+        workspace=workspace_svc,
+        notifications=AsyncMock(),
+        notification_delivery=AsyncMock(),
+        evidence_repo=evidence_repo,
+    )
+
+
+def _task_with_pr(task_id: object, *, commits: list[str]) -> MagicMock:
+    return MagicMock(
+        id=task_id,
+        status="awaiting_qa",
+        assigned_to=None,
+        branch_name="feature/backend/abc12345--def67890",
+        work_session_id=uuid4(),
+        commits=commits,
+        pr_number=20,
+        pr_url="https://github.com/org/repo/pull/20",
+        dev_notes="see PR description",
+        acceptance_criteria_status=[],
+    )
+
+
+@pytest.mark.asyncio
+async def test_evidence_populates_files_changed_from_git() -> None:
+    """The smoke-9 regression: PR #20 has README change on GitHub but
+    evidence() reports files_changed=[]. The fix queries git directly."""
+    agent_id = uuid4()
+    task_id = uuid4()
+    task_svc = AsyncMock()
+    task_svc.get.return_value = _task_with_pr(task_id, commits=["abc", "def"])
+    git_svc = AsyncMock()
+    git_svc.diff.return_value = "diff --git a/README.md b/README.md\n+added line\n"
+    git_svc.list_changed_files.return_value = ["README.md", "docs/guide.md"]
+    workspace_svc = AsyncMock()
+    evidence_repo = AsyncMock()
+    evidence_repo.journal_highlights_for_task.return_value = []
+
+    ca = ContentActions(
+        _deps_for_evidence(task_svc, git_svc, workspace_svc, evidence_repo)
+    )
+    env = await ca.evidence(agent_id=agent_id, task_id=task_id)
+    body = env.as_dict()
+
+    assert body["error"] is None
+    assert body["evidence"]["files_changed"] == ["README.md", "docs/guide.md"]
+    assert "diff --git" in body["evidence"]["pr_diff_summary"]
+    git_svc.list_changed_files.assert_awaited_once()
+
+
+@pytest.mark.asyncio
+async def test_evidence_uses_full_pr_diff_not_head_minus_one() -> None:
+    """git.diff must be called with base=None (full PR diff vs parent),
+    not base='HEAD~1' (only the last commit)."""
+    agent_id = uuid4()
+    task_id = uuid4()
+    task_svc = AsyncMock()
+    # Multi-commit branch — the pre-fix code passed base='HEAD~1' when
+    # task.commits was non-empty, masking earlier commits' changes.
+    task_svc.get.return_value = _task_with_pr(task_id, commits=["sha1", "sha2", "sha3"])
+    git_svc = AsyncMock()
+    git_svc.diff.return_value = "full diff"
+    git_svc.list_changed_files.return_value = []
+    workspace_svc = AsyncMock()
+    evidence_repo = AsyncMock()
+    evidence_repo.journal_highlights_for_task.return_value = []
+
+    ca = ContentActions(
+        _deps_for_evidence(task_svc, git_svc, workspace_svc, evidence_repo)
+    )
+    await ca.evidence(agent_id=agent_id, task_id=task_id)
+
+    git_svc.diff.assert_awaited_once()
+    call_kwargs = git_svc.diff.await_args.kwargs
+    # Pre-fix bug: kwargs['base'] would be 'HEAD~1' for any multi-commit
+    # branch. Post-fix: base is omitted (or explicitly None).
+    base = call_kwargs.get("base")
+    assert base in (None, ""), (
+        f"git.diff must use full-PR diff (base=None), got base={base!r}"
+    )
+    assert call_kwargs.get("branch_name") == "feature/backend/abc12345--def67890"
+
+
+@pytest.mark.asyncio
+async def test_evidence_populates_journal_highlights() -> None:
+    """evidence() must return journal_highlights so QA gets the dev's
+    decision/reflection context — same as qa.py's claim_review evidence."""
+    agent_id = uuid4()
+    task_id = uuid4()
+    task_svc = AsyncMock()
+    task_svc.get.return_value = _task_with_pr(task_id, commits=["abc"])
+    git_svc = AsyncMock()
+    git_svc.diff.return_value = ""
+    git_svc.list_changed_files.return_value = []
+    workspace_svc = AsyncMock()
+    evidence_repo = AsyncMock()
+    highlights = [
+        {"scope": "decision", "title": "Use README format X", "content": "..."},
+        {"scope": "reflect", "title": "Lesson learned", "content": "..."},
+    ]
+    evidence_repo.journal_highlights_for_task.return_value = highlights
+
+    ca = ContentActions(
+        _deps_for_evidence(task_svc, git_svc, workspace_svc, evidence_repo)
+    )
+    env = await ca.evidence(agent_id=agent_id, task_id=task_id)
+    body = env.as_dict()
+    assert body["evidence"]["journal_highlights"] == highlights
+    evidence_repo.journal_highlights_for_task.assert_awaited_once_with(task_id)
+
+
+@pytest.mark.asyncio
+async def test_evidence_no_branch_skips_git_calls() -> None:
+    """A task without a branch_name has no PR yet — skip git entirely,
+    still return a valid envelope with empty files_changed."""
+    agent_id = uuid4()
+    task_id = uuid4()
+    task_svc = AsyncMock()
+    no_branch = MagicMock(
+        id=task_id,
+        status="claimed",
+        assigned_to=agent_id,
+        branch_name=None,
+        work_session_id=None,
+        commits=[],
+        pr_number=None,
+        pr_url=None,
+        dev_notes=None,
+        acceptance_criteria_status=[],
+    )
+    task_svc.get.return_value = no_branch
+    git_svc = AsyncMock()
+    workspace_svc = AsyncMock()
+    evidence_repo = AsyncMock()
+    evidence_repo.journal_highlights_for_task.return_value = []
+
+    ca = ContentActions(
+        _deps_for_evidence(task_svc, git_svc, workspace_svc, evidence_repo)
+    )
+    env = await ca.evidence(agent_id=agent_id, task_id=task_id)
+    body = env.as_dict()
+    assert body["error"] is None
+    assert body["evidence"]["files_changed"] == []
+    assert body["evidence"]["pr_diff_summary"] == ""
+    git_svc.diff.assert_not_awaited()
+    git_svc.list_changed_files.assert_not_awaited()