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_reassignment.py

@@ -97,7 +97,8 @@ async def test_i_am_done_reassigns_task_to_qa_agent() -> None:
         # Gate Set E requires non-empty commits before submit_qa.
         commits=[{"sha": "abc"}],
         documents=[],
-        dev_notes="",
+        # i_am_done obligates the developer's dev_notes section (>=40 chars).
+        dev_notes="Implemented the change and added tests covering the new path.",
     )
     after_verify = MagicMock(
         **{**initial.__dict__, "status": "verifying", "self_verified": True},
@@ -162,7 +163,8 @@ async def test_i_am_done_skips_reassign_when_no_qa_agent() -> None:
         # Gate Set E requires non-empty commits before submit_qa.
         commits=[{"sha": "abc"}],
         documents=[],
-        dev_notes="",
+        # i_am_done obligates the developer's dev_notes section (>=40 chars).
+        dev_notes="Implemented the change and added tests covering the new path.",
     )
     after_verify = MagicMock(
         **{**initial.__dict__, "status": "verifying", "self_verified": True},