refactor: drop cross-project spec-validation parser machinery

The fence-label -> parser fact, the specify/grounding-check/planner
parse gates, the parse-trace attestation, and all their cross-references
served a single real user (ailang). Convention over configuration: the
generic machinery is removed plugin-wide; the one consumer carries an
equivalent project-local directive in its own CLAUDE.md.

Archive under docs/plans and docs/specs left intact as time documents.

README.md

@@ -92,9 +92,6 @@ project's own `CLAUDE.md` under `## Skills plugin: project facts`:
 - Regression scripts; architect sweeps
 - Design ledger / glossary / contracts / models / bench / public
   interface / fieldtest-examples paths
-- Spec-validation parsers (fence label → `{ext, cmd}`, `cmd` carrying
-  the `{file}` placeholder; a label with no entry is a documented
-  skip, never a silent pass)
 - Per-role standing reading
 - Issue-tracker repo slug + list / show commands
 - Spec auto-sign (off by default)
@@ -115,8 +112,8 @@ auto-sign in its CLAUDE.md project facts.
 With it on, the orchestrator may sign a spec in the user's place, but
 never on its own confidence. Signing requires two stages to clear:
 
-- **Objective gates** — the precondition gate, the parse-every-block
-  gate, and a `grounding-check` `PASS` with no human override.
+- **Objective gates** — the precondition gate and a `grounding-check`
+  `PASS` with no human override.
 - **A unanimous adversarial panel** — the `spec-skeptic` agent
   dispatched five times in parallel, one per lens (`criterion`,
   `grounding`, `scope-fork`, `ambiguity`, `plan-readiness`), each