feat(content): obligate role note sections like journals

Completes the note(scope='handoff') write-path (WIP 23e6ee57): every role
with a dedicated note section is now obligated to populate it, the same way
journals are obligated.

Obligations (foundation.policy.tracing):
- DEV_NOTES / PR_REVIEWER_NOTES / QUICK_CONTEXT_MIN_CHARS requirements +
  checkers, wired onto i_am_done (dev_notes), delegate (quick_context), and
  pr_pass / pr_fail / post_pr_review (pr_reviewer_notes).
- Fixes a latent bug: the docs-notes checker read dev_notes instead of
  doc_notes (the documenter's section); the i_documented shim now feeds
  doc_notes to match.

Auditor: a session-scoped note obligation on i_am_idle — the auditor owns no
delivery task and has no delivery verb, so it must have recorded an
observation within the window before going idle (JournalService.has_recent_entry).

Write-then-gate: persisted sections (dev_notes / quick_context) are
pre-written by the agent's note(scope='handoff') before the gated verb;
argument-borne sections (doc_notes / pr_reviewer_notes) are checked through a
SimpleNamespace shim, the same pattern qa_notes already uses.

Config: dev/pr_reviewer/quick_context min-chars (40/40/30), panel-tunable.
Plus per-gap remediation hints and full coverage (write-path routing,
ownership, validation->remediation, each obligation, the doc_notes fix).

Full make-quality green: 9777 passed, 95.6% coverage.

tests/unit/gateway/test_choreographer_dev.py

@@ -428,7 +428,7 @@ async def test_i_am_done_blocks_when_acceptance_criteria_unaddressed() -> None:
         pr_url="https://x/pr/8",
         team="backend",
         documents=[],
-        dev_notes="",
+        dev_notes="Implemented the change and added tests covering the new path.",
     )
     task_svc = AsyncMock()
     task_svc.get.return_value = t
@@ -480,7 +480,7 @@ async def test_i_am_done_reflect_note_addresses_acceptance_criteria() -> None:
         pr_url="https://x/pr/8",
         team="backend",
         documents=[],
-        dev_notes="",
+        dev_notes="Implemented the change and added tests covering the new path.",
         qa_notes="",
     )
     task_svc = AsyncMock()
@@ -534,7 +534,7 @@ async def test_i_am_done_blocks_when_journal_reflect_missing() -> None:
         pr_url="https://x/pr/8",
         team="backend",
         documents=[],
-        dev_notes="",
+        dev_notes="Implemented the change and added tests covering the new path.",
     )
     task_svc = AsyncMock()
     task_svc.get.return_value = t
@@ -717,7 +717,7 @@ def _passing_i_am_done_task(agent_id: Any, task_id: Any) -> Any:
         pr_url="https://x/pr/8",
         team="backend",
         documents=[],
-        dev_notes="",
+        dev_notes="Implemented the change and added tests covering the new path.",
         qa_notes="",
     )