docs(openspec): reconcile two stale task checklists against the tree

body-double-own-agent-picker sat at 0/40 despite being substantially
shipped: the checklist was authored 2026-07-25 and never ticked as the
work landed, then the codebase moved past it twice (inline script
extracted to js/components/, ttyd retired via ADR-0008 which deleted
terminalPanel/splitLayout and two test files wholesale). Audited every
box against the tree: now 29/40 — 23 built with evidence pointers,
6 superseded with the reason recorded, 11 genuinely open (ADR status
flips, the sessionType dead-state deletion, the prescribed cross-fire
and 409 tests, manual browser verification, teaching-moment banking).

herdr-ghostty-multiplexer-transport re-audited from 53/67 to 56/67:
the test_clean.py mock migration had landed (:255), test_orchestrator.py
was deleted outright, and the full suite ran green at HEAD (4790 unit /
504 e2e). The 11 remaining boxes are real gaps — chiefly the six T4.2
journey tests and the default flip they block. herdr and ghostty both
remain opt-in only (STUDYLOOP_MULTIPLEXER=herdr; studyloop web --dev),
so the change stays open, correctly.

spec-check: 22 passed, 0 failed.

Author: NetDevAutomate