fix: Chief gets a face, Hunt Plan speaks tribe, finish the #798 rename

[quadseven]

Size: S

Why

Three things visible in one screenshot of a grug email.

1. Chief had no face

Elder's inline review leads with its portrait. Chief's board section was the one
persona talking without one.

grug_chief.png verified live as a real image/png. Drum, Haunt, Totem and
Teller have no asset - grug.lol returns the SPA index.html for those paths,
so a 200 there is not proof and an <img> would render a broken image rather
than a portrait. Chief only, until those assets exist.

2. #798 renamed the check titles and stopped there

Every renamed persona kept saying its old name in the one place a human reads it:

where	was	now
nudge.py body	Grug Pulse see this PR sleep...	Grug Drum beat for this PR
nudge.py summary	Pulse nudge - PR quiet	Drum nudge
sentinel x2	Grug Sentinel notice:	Grug Haunt notice:
warder x3	Grug Warder count the marks	Grug Totem count the marks

Markers and config keys deliberately unchanged. The nudge marker in particular
is how that module finds its own prior comments - renaming it would make it
blind to them and double-post. Display renames, key stays (ADR-0002).

3. The plan gate did not read the plan

check_scope_fence tested only that ## Out of scope existed. Paste the
template, leave it blank, gate passes.

That is the same "an unfilled template should NOT pass" defect already fixed for
bullets in #20 and enforced by check_why's word floor. Scope-fence was the one
check in the module still testing presence rather than content. An empty fence
is worse than no fence - it reads as the author having considered scope and
found nothing to exclude.

Non-empty is the whole bar, deliberately. A first attempt required 3+ words
and the existing suite rejected it: Deferred. and Not now. are real answers,
and a gate that demands padding gets padding.

Check rows also now read as tribe rather than jira:

| why hunt            | pass | ## Why has 5 words
| what good look like | pass | 3 bullets
| how big             | pass | Size: M
| where stop          | fail | ## Out of scope is empty - name what this does NOT touch
| which ticket        | warn | no `closes #N` link in body
| ticket done         | pass | no linked issues

Display only. CheckResult.name is load-bearing - _ADVISORY_CHECKS keys
off it to decide blocking-vs-warn, and Chief's issue-time remedy text keys off
it too. Renaming the values would silently make issue-link blocking. Pinned by
a test.

Acceptance criteria

• Chief's advisory carries a portrait, verified as a real image not an SPA fallback
• No persona speaks a retired name in user-facing text
• Markers and config keys unchanged, so no double-posting
• An empty ## Out of scope fails the gate
• A terse but real fence (Deferred.) still passes
• Check rows show caveman labels while keys stay machine-readable
• The advisory/blocking split still keys off the real name
• Every check has a display name, so none renders as a bare key

Out of scope

• Portraits for Drum, Haunt, Totem and Teller. The assets do not exist; adding
  <img> tags would render broken images. Worth doing when the art exists.
• Renaming the pulse/warder/sentinel module directories and config keys.
  Those are historical keys per ADR-0002 and changing them is a migration, not a
  rename.
• Raising ## Why's 5-word floor, or any other threshold. Only the empty-section
  hole is closed here.

Verification

• 1840 passed, 2 skipped
• Hunt Plan table and Chief advisory both rendered and inspected by hand
• Portrait URLs probed for content-type, not just status code

Part of #791.