feat: live status-board comment + full-fleet dogfood (#1)

Phase 3: one consolidated, live-updating PR comment aggregating every
model's per-lens progress (queued -> running -> finished + verdict), so
the swarm's progress is visible at a glance and a watcher can tell when
it's done. Opt-in statusWriter in the binary (atomic writes) + a
background status-board.sh renderer wired through entrypoint.sh; default
on, GADFLY_STATUS_BOARD=0 to disable.

Also restores gadfly's dogfood swarm to the full cloud fleet (9 cloud +
M5; M1 dropped as too slow) matching mort, and folds in the 3 real bugs
the swarm found on its own PR (skip-binary stuck-waiting, panic-stuck
lens, busy-loop on bad poll interval). All 36 findings graded via the
gadfly MCP (18 real / 18 false-positive).

gofmt clean, go vet quiet, go build + go test -race green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Co-authored-by: Steve Dudenhoeffer <steve@stevedudenhoeffer.com>
Co-committed-by: Steve Dudenhoeffer <steve@stevedudenhoeffer.com>

CLAUDE.md

@@ -39,6 +39,7 @@ cmd/gadfly/            the reviewer binary — pure producer of review markdown
   recheck.go           second-pass verification prompt + verdict recompute
   *_test.go            sandbox, recheck, wrap-up, spec/endpoint-parse, specialist-resolution tests
 scripts/run.sh         fetch PR diff+meta, run the binary, upsert ONE labeled PR comment
+scripts/status-board.sh    render+upsert ONE live status-board comment (per-model/per-lens progress)
 scripts/system-prompt.txt   the reviewer persona + verification discipline (generic, not repo-specific)
 entrypoint.sh          container brains: trigger gating, PR clone, model loop (the logic that
                        used to live in workflow YAML)