fix(implement-loop): hold plan-contradicting quality findings instead of oscillating to a false BLOCKED

The per-task quality re-loop treated every `changes_requested` as
"deviate to satisfy", and the quality-repair dispatch was not even
given the task text. When a finding's only remedy contradicted a
plan-prescribed name/signature, the implementer renamed off-plan, the
next review flagged "diverges from plan", and the loop oscillated
name-misleads <-> diverges-from-plan until the retry cap, emitting a
false BLOCKED on code that was green the whole time.

Fix (issue's option 2 — the plan knowledge lives with the implementer,
which holds the task text; the quality-reviewer is deliberately blind
to it, so option 1 would have breached that separation):

- The quality-repair dispatch now receives the task text and a HOLD
  CLAUSE. A cosmetic finding (plan kept => build+tests green) is KEPT
  and recorded in a new `held` field; the loop surfaces it as a concern
  instead of chasing a deviation. A finding the implementer judges
  correctness-breaking escalates to BLOCKED, never a silent hold.
- The hold is keyed on two structural signals, never on a self-reported
  status enum (which the implementer contract overloads): the `held`
  array, and a no-op backstop over a required `diff_fingerprint` (a
  changes_requested verdict over an already-seen diff-state means the
  repair was a no-op or cycled back — re-running quality is futile).
  Fingerprints are tracked in a Set so A-B-A edit-then-revert is caught.
- A no-op-backstop concern is labelled neutrally (a byte-identical diff
  cannot tell a principled plan-hold from an ignored bug); implement
  SKILL.md Step 3 now routes a held/unresolved quality finding to
  orchestrator hand-verification before committing, even under /boss.

The held/no-op partition is the implementer's judgement, not enforced
in code — the residual fail-open is bounded to cosmetic-on-green
findings and disclosed, with the orchestrator's Step-3 inspection as
the backstop, the same trust placed in its other self-reports. Verified
across three rounds of adversarial review (held-the-plan paths, fail-
open laundering, schema/Set mechanics) — all closed.

closes #10

implement/SKILL.md

@@ -178,6 +178,13 @@ is no `BLOCKED.md` (DONE never writes one).
    that the diff itself does not: the *why*, the alternatives
    considered and rejected, the verification steps run, and any
    concerns that remain. Detail-fill comes from the end-report.
+   A concern phrased as a *held* or *unresolved quality finding* (the
+   per-task quality gate kept a plan-prescribed element against a
+   reviewer finding, or a repair was a no-op) is the gate handing you
+   the judgement it could not make in code: verify that finding by
+   hand against the diff before committing — do not auto-sign past it,
+   even under `/boss`. Keep it if it is a principled plan-hold; if it
+   is an unaddressed defect, send the iter back rather than commit.
 4. Stage + commit the code edits and the stats file.
 5. If the trigger is done-state and the user is away, run the project's
    configured notification command per `../boss/SKILL.md` "Done-state