feat(21-22): agente AI generazione preventivo + pagina pubblica deck

- Migration 0010: tabella proposals (id, slug, lead_id, client_id,
  offer_macro_id, content jsonb, state, selected_tier, accepted_at)
  applicata a prod via SSH tunnel
- @anthropic-ai/sdk@0.105.0 installato; ANTHROPIC_API_KEY in .env.local
- src/lib/proposal/: schema Zod ProposalContent, agente Claude Opus 4.8,
  assemble (AI + offerta DB + config consulente), queries, profile.ts
- Admin: /admin/preventivi lista + /genera (pre-fill ?lead_id=X) + /[id] review
- Sidebar: voce Preventivi + CTA globale lime "Genera preventivo"
- LeadDetail: pulsante "Genera preventivo" → /admin/preventivi/genera?lead_id=X
- Pagina pubblica /preventivo/[slug]: deck 20+ slide light-mode iamcavalli,
  navigazione frecce + dot + keyboard, accept/reject con guard immutabilità
- STATE.md aggiornato (80%), 21-PLAN.md scritto nel formato GSD

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.planning/STATE.md

@@ -3,15 +3,15 @@ gsd_state_version: 1.0
 milestone: v2.2
 milestone_name: — Sales Loop
 status: executing
-stopped_at: "Phase 19 completa (19-01 done). Pronta per /gsd-plan-phase 20"
-last_updated: "2026-06-19T18:05:00.000Z"
-last_activity: 2026-06-19 -- Phase 19 complete — LeadsKanbanBoard + LeadsViewToggle (PIPE-01/PIPE-02)
+stopped_at: "Phase 21+22 codice completo — pending: (1) migration 0010 a prod via SSH tunnel; (2) dati reali in profile.ts"
+last_updated: "2026-06-20T14:00:00.000Z"
+last_activity: 2026-06-20 -- Phase 21+22 eseguite insieme — agente AI Opus 4.8 + deck pubblico 20+ slide + entry point LeadDetail + sidebar globale
 progress:
   total_phases: 5
-  completed_phases: 2
-  total_plans: 4
-  completed_plans: 4
-  percent: 40
+  completed_phases: 4
+  total_plans: 7
+  completed_plans: 6
+  percent: 80
 ---
 
 # Project State
@@ -26,10 +26,10 @@ See: .planning/PROJECT.md (updated 2026-06-13)
 
 ## Current Position
 
-Phase: 20 (R3) Knowledge Base Cliente — pending planning
-Plan: —
-Status: Ready to plan
-Last activity: 2026-06-19 -- Phase 19 complete (19-01 done — PIPE-01/PIPE-02 verified)
+Phase: 20 (R3) Knowledge Base Cliente — ready to execute
+Plan: 3 piani (20-01 migration, 20-02 data layer, 20-03 UI)
+Status: Ready to execute
+Last activity: 2026-06-19 -- Phase 20 planned (3 piani, verification passed — KB-01/KB-02)
 
 Progress (v2.2): [████░░░░░░] 40% — 2/5 fasi complete