docs(kiro): archive the superseded roadmap; status notes on specs

A4: roadmap-2026-09-04.md moves to .kiro/archive/steering/ so it no longer
loads as steering (roadmap.md and safety-net.md replaced it); roadmap.md's
pointer follows it. overview.md's spec table is recounted from tasks.md and
spec.json (adds ai-service-plane, harnessx-removal, learned-decision-engine,
pre-push-safety-net; drops the stale "active one"), and the module line now
cites the regenerated audit: 150 modules, 145 load-bearing, 5 standalone,
0 orphaned; 1,964 tests collected.

A5: a dated status note at the top of the requirements (or brief) of 16
specs: retired, superseded, dormant or complete, and for
model-grounded-detection the removal of judge/calibrate/execution (closing
the Req 10 execution-tier option). spec.json phase corrected to
implementation-complete where every task is checked (model-grounded-
detection, propose-adjudicate-prove, tree-sitter-overlay-extra,
corpus-seeded-mechanisms, pair-corpus-honesty); openrouter-sast-harness gets
a spec.json with status retired. Nothing deleted, no spec moved.

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01EmM1j46qgKMh3zqD1QMwEo

.kiro/specs/corpus-seeded-mechanisms/requirements.md

@@ -1,5 +1,7 @@
 # Requirements Document
 
+> **Status 2026-10-02:** complete, 17 of 17 tasks (spec.json phase corrected to `implementation-complete`). Its `[variants]` config keys were retired on 2026-10-02: the variant search they configured (`semantic/variants.py`) had already been deleted.
+
 ## Introduction
 
 OpenUltraSAST's labeled pair corpus measures the detector but does not improve it, and its mechanism memory is empty because only sandbox-proven findings may write to it. This spec turns every trusted pair into a mechanism record, adds a structural variant search that proposes matches on any scanned tree, measures the corpus's own detection rate leave-one-out, and gives the improve loop a lever that can raise recall under the existing false-positive ceiling and per-profile holdout gate.

.kiro/specs/corpus-seeded-mechanisms/spec.json

@@ -1,9 +1,9 @@
 {
   "feature_name": "corpus-seeded-mechanisms",
   "created_at": "2026-09-05T06:18:31Z",
-  "updated_at": "2026-09-05T16:30:00Z",
+  "updated_at": "2026-10-02T00:00:00Z",
   "language": "en",
-  "phase": "implementation",
+  "phase": "implementation-complete",
   "approvals": {
     "requirements": {
       "generated": true,