fix(task-logs): a collaborator who may write a task may log on it (rule 78)

create_log filtered on Note.user_id == user_id, a bare owner check, so a
collaborator with write access to a shared task was told it did not exist
— and, since a log now stamps the claim, could never be seen working it.
It now asks can_write_note. Editing and deleting a log still require its
author, which is authorship rather than access.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/test_task_claims.py

@@ -283,3 +283,19 @@ async def test_ending_a_session_releases_only_that_sessions_claims(users):
     assert (await notes_svc.get_note(owner, gone.id)).claimed_at is None
     assert (await notes_svc.get_note(owner, kept.id)).claim_session == "sess-stays"
     assert await tc.release_session(owner, "") == 0
+
+
+@pytest.mark.integration
+async def test_a_collaborator_with_write_access_can_log_and_so_claims(users):
+    """create_log used to filter on the task's OWNER (a rule #78 violation), so
+    a collaborator on a shared task could not log on it — nor, since logging
+    stamps the claim, ever be seen working it."""
+    from scribe.services import sharing, task_logs
+
+    owner, collaborator = users
+    task = await notes_svc.create_note(owner, title="shared work", status="todo")
+    await sharing.share_note(owner, task.id, target_user_id=collaborator,
+                             permission="editor")
+    await task_logs.create_log(collaborator, task.id, "picked this up")
+    got = await notes_svc.get_note(owner, task.id)
+    assert got.claimed_by == collaborator