📝 docs(adr): audit and update Status for 5 implemented ADRs

Audits 7 ADRs marked "Proposed" against the actual code, updates the Status
field of 5 that are at least partially implemented. Keeps 2 as "Proposed"
because only test infrastructure exists (no production implementation).

Updated:
- 0018 user-management-auth-system : Partially Implemented (auth/jwt/repos exist; auth middleware + greet integration missing)
- 0019 postgresql-integration : Partially Implemented (postgres repo exists, BDD uses it; sqlite still present, not default)
- 0022 rate-limiting-cache-strategy : Implemented (Phase 1) - Phase 2 still Proposed (PRs #22 ratelimit, #23 cache; Redis/Dragonfly deferred)
- 0024 bdd-test-organization-and-isolation : Partially Implemented (domain dirs + scenario state isolation; parallel exec opt-in only)
- 0025 bdd-scenario-isolation-strategies : Partially Implemented (schema-per-scenario opt-in via BDD_SCHEMA_ISOLATION; cache/user store isolation missing)

Kept "Proposed" (production code not implemented, only test fixtures):
- 0021 jwt-secret-retention-policy (BDD scenarios exist but no ConfigManager / cleanup goroutine in pkg/)
- 0023 config-hot-reloading (testserver has reload, but no Viper WatchConfig in production)

Audit method: Q-024 compliant - every status decision has file:line evidence
documented in workspaces/adr-audit-status/stages/01-audit/output/audit-report.md.

Generated ~95% in autonomy by Mistral Vibe via ICM workspace
~/Work/Vibe/workspaces/adr-audit-status/. Cost €2.50 stage 01-audit (very thorough).
Trainer (Claude) finalized commit/PR (Mistral hit max-price).

🤖 Co-Authored-By: Mistral Vibe (devstral-2 / mistral-medium-3.5)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

adr/0018-user-management-auth-system.md

@@ -1,7 +1,7 @@
 # 18. User Management and Authentication System
 
 **Date:** 2026-04-06
-**Status:** Proposed
+**Status:** Partially Implemented
 **Authors:** Product Owner
 **Decision Drivers:** Security, User Personalization, Admin Functionality
 

adr/0019-postgresql-integration.md

@@ -1,7 +1,7 @@
 # 19. PostgreSQL Database Integration
 
 **Date:** 2026-04-07
-**Status:** Proposed
+**Status:** Partially Implemented
 **Authors:** Product Owner
 **Decision Drivers:** Data Persistence, Scalability, Production Readiness
 

adr/0022-rate-limiting-cache-strategy.md

@@ -1,6 +1,6 @@
 # ADR 0022: Rate Limiting and Cache Strategy
 
-**Status:** Proposed
+**Status:** Implemented (Phase 1) - Phase 2 still Proposed
 
 ## Context
 

adr/0024-bdd-test-organization-and-isolation.md

@@ -1,6 +1,6 @@
 # ADR 0024: BDD Test Organization and Isolation Strategy
 
-**Status:** Proposed
+**Status:** Partially Implemented
 
 ## Context
 

adr/0025-bdd-scenario-isolation-strategies.md

@@ -1,6 +1,6 @@
 # ADR 0025: BDD Scenario Isolation Strategies
 
-**Status:** Proposed
+**Status:** Partially Implemented
 
 ## Context