enh(#966): gate behavior-dependent truths on behavioral evidence in gsd-verifier (#1271)

* enh(#966): gate behavior-dependent truths on behavioral evidence in gsd-verifier

Introduce a per-truth PRESENT_BEHAVIOR_UNVERIFIED state for must-haves that assert a state transition or a cancellation/cleanup/ordering invariant whose only evidence is symbol presence + wiring. Such truths are excluded from the verified_truths score, reported as a behavior_unverified count, recorded in an always-on behavior_unverified_items frontmatter list, and routed to the existing human_needed sink — so a clean N/N can no longer be reached on symbol presence alone.

The overall-status vocabulary and the src/verification.cts seam are unchanged (the new state is per-truth only); gaps_found keeps decision-tree precedence; override-passed truths still count toward verified_truths. Mirrors the calibration into the shipped verify-phase.md workflow (with an infra/foundation carve-out), the VERIFICATION.md templates, and docs (planning-artifacts.md, AGENTS.md). gsd-verifier.md kept under its 48KB LARGE cap; size baselines regenerated.

Closes #966

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* chore(#966): add changeset fragment for gsd-verifier behavior-unverified calibration

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

tests/workflow-size-baseline.json

@@ -85,6 +85,6 @@
   "undo.md": 10431,
   "update.md": 21053,
   "validate-phase.md": 10745,
-  "verify-phase.md": 30875,
+  "verify-phase.md": 33161,
   "verify-work.md": 31157
 }