feat(spec-phase): prohibition probe — surface "must-NOT" constraints (#644) (#1149)

Adds the spec-time prohibition probe (spec-phase Step 5.6) — the second adapter of the probe-core resolution model. Surfaces unwritten must-NOT constraints as negative SPEC acceptance criteria with test/judgment verification tiers; fail-closed at verify time. Per ADR-550. Closes #644.

tests/workflow-size-baseline.json

@@ -51,7 +51,7 @@
   "note.md": 6563,
   "pause-work.md": 14397,
   "plan-milestone-gaps.md": 11765,
-  "plan-phase.md": 92120,
+  "plan-phase.md": 92759,
   "plan-review-convergence.md": 23468,
   "plant-seed.md": 11741,
   "pr-branch.md": 9561,
@@ -72,7 +72,7 @@
   "ship.md": 24388,
   "sketch-wrap-up.md": 14223,
   "sketch.md": 19960,
-  "spec-phase.md": 23094,
+  "spec-phase.md": 27589,
   "spike-wrap-up.md": 15092,
   "spike.md": 24517,
   "stats.md": 6718,
@@ -85,6 +85,6 @@
   "undo.md": 10431,
   "update.md": 21053,
   "validate-phase.md": 10745,
-  "verify-phase.md": 28430,
+  "verify-phase.md": 30875,
   "verify-work.md": 31157
 }