docs(skill): prescribe solved-question recall in F4/F6/F7; refresh PROJECT_STATE

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

PROJECT_STATE.md

@@ -78,6 +78,32 @@ Opens frontend at http://localhost:5173 → backend :8787.
 - Global user rules (`~/.claude/CLAUDE.md`): think before coding, simplicity first, surgical
   changes, goal-driven verification.
 
+## Active memory — F8 promotion gate + solved-question recall — SHIPPED, L2 pending (2026-07-07)
+
+Two additions to close the loop on reusable memory, on top of the existing `tht memory
+search` (Phase 2) reuse:
+
+- **F8 promotion gate.** `reviewer_memory_promote` (Phase 8, called with only the session
+  id): the gate computes candidates deterministically via `tht memory promote --preview
+  --json` (the 3 reusable decision types, already excluding previously promoted/declined
+  ones) and shows a pre-selected checklist. Selected → `tht memory save-one` persists to
+  the vectordb + records `memory_promoted`; deselected → `memory_promotion_declined`
+  (ledger detail `seq:<n>`) so it is never re-proposed. `tht memory promote`/`save-one` were
+  added to the gate's anti-bypass FORBIDDEN list (model must go through the gate tool).
+- **Solved-question exemplars.** New vector kind `solved_question` reusing the existing
+  `memory` pgvector table (no server-side DDL); `harness/tht/solved.py` does a one-row
+  upsert keyed by a hash of question+SQL. CLI: `tht memory solved-index` / `solved-search`.
+  `tht session finalize` auto-indexes the pair (best-effort: green line on upsert, cyan
+  "già aggiornata" on dedup no-op, yellow warning + the recovery command
+  `tht memory solved-index <id>` on failure). `SKILL.md` now prescribes calling
+  `solved-search` as reference-only context in F4 (schema linking), F6 (CTE plan) and F7
+  (final SQL), and documents the finalize auto-index in "Session end".
+
+**Pending L2 gate (not yet run — needs VPN + writer key):** one live end-to-end session on
+workspace `psd` via `./scripts/run-stack.sh` to verify (a) the promotion checklist renders
+pre-selected and persists selected/declined correctly, (b) finalize indexes the pair,
+(c) `tht memory solved-search` returns it with sql + tables.
+
 ## Review gates v2 — payload strutturati + viewer dedicati — COMPLETE (2026-07-07)
 
 Plan: `~/.claude/plans/prima-di-passare-ai-inherited-marshmallow.md`. Merged to `main` @ `2410f01`