📝 docs: audit and correct all ADR statuses and content

Full pass over all 25 ADRs to align documentation with actual
implementation state. Changes by ADR:

README index: completely rewritten — previous table mapped numbers to
wrong titles from 0010 onward.

0008 (BDD Testing): added note that flat features/ structure and godog
CLI invocation are superseded by ADR-0024; framework decision stands.

0009 (Hybrid Testing): renamed from "Combine BDD and Swagger-based
testing" to "BDD Testing with OpenAPI Documentation"; clarified that
the SDK-testing layer was never built and has no open issue.

0013 (OpenAPI/Swagger): removed leftover merge conflict artifact
(=======) and duplicated 60-line block.

0015 (Cobra CLI): fixed status contradiction — body said "Implemented"
while footer said "Proposed". Now Accepted.

0018 (User Management): status Proposed → Accepted; system is fully
implemented (JWT, bcrypt, GORM repos all present).

0019 (PostgreSQL): status Proposed → Accepted (Partial); added warning
that sqlite_repository.go and gorm/driver/sqlite still present contrary
to ADR intent.

0021 (JWT Retention): fixed wrong cross-reference (previously cited
ADR-0009 "Hybrid Testing" as source of JWT multi-secret support); fixed
title number from "10" to "21"; clarified that base JWT is implemented
but the retention cleanup job is not.

0022 (Rate Limiting/Cache): added warning block linking to open Gitea
issue #13; changed all 20 false ✅ implementation checkboxes to ❌.

0023 (Config Hot Reloading): added note that BDD scenarios exist for
this feature but the feature itself is not yet implemented.

0024 (BDD Organization): status Proposed → Accepted; modular domain
structure is fully built.

0025 (BDD Scenario Isolation): status Proposed → Accepted (Partial);
Phase 1 done, Phase 2 blocked on ADR-0022.

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

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

@@ -3,6 +3,8 @@
 ## Status
 **Proposed** 🟡
 
+> **⚠️ Not yet implemented.** Gitea issue #13 ("feat: Implement Rate Limiting and Caching Strategy") is open and tracks this work. `go-cache`, `redis`, and `ulule/limiter` are absent from `go.mod`. The phase checkboxes below are corrected to reflect actual status.
+
 ## Context
 
 As the dance-lessons-coach application grows and potentially serves multiple users simultaneously, we need to implement rate limiting to:
@@ -284,38 +286,38 @@ func GetCacheKey(prefix, entityType, entityID string) string {
 ## Implementation Phases
 
 ### Phase 1: In-Memory Cache (Current Sprint)
-- ✅ Research and select in-memory cache library
-- ✅ Implement cache interface and in-memory service
-- ✅ Add cache configuration to config package
-- ✅ Implement basic cache operations (set, get, delete)
-- ✅ Add TTL support and automatic cleanup
-- ✅ Cache JWT validation results
-- ✅ Add cache metrics and monitoring
+- ❌ Research and select in-memory cache library
+- ❌ Implement cache interface and in-memory service
+- ❌ Add cache configuration to config package
+- ❌ Implement basic cache operations (set, get, delete)
+- ❌ Add TTL support and automatic cleanup
+- ❌ Cache JWT validation results
+- ❌ Add cache metrics and monitoring
 
 ### Phase 2: Redis-Compatible Cache (Next Sprint)
-- ✅ Set up Dragonfly/KeyDB in development environment
-- ✅ Implement Redis cache service
-- ✅ Add configuration for Redis connection
-- ✅ Implement cache fallback strategy (Redis → in-memory)
-- ✅ Add health checks for Redis connection
-- ✅ Implement distributed cache invalidation
+- ❌ Set up Dragonfly/KeyDB in development environment
+- ❌ Implement Redis cache service
+- ❌ Add configuration for Redis connection
+- ❌ Implement cache fallback strategy (Redis → in-memory)
+- ❌ Add health checks for Redis connection
+- ❌ Implement distributed cache invalidation
 
 ### Phase 3: Rate Limiting (Following Sprint)
-- ✅ Research and select rate limiting library
-- ✅ Implement rate limiter service
-- ✅ Add rate limit configuration
-- ✅ Implement Chi middleware for rate limiting
-- ✅ Add rate limit headers to responses
-- ✅ Implement IP whitelisting
-- ✅ Add endpoint-specific rate limits
+- ❌ Research and select rate limiting library
+- ❌ Implement rate limiter service
+- ❌ Add rate limit configuration
+- ❌ Implement Chi middleware for rate limiting
+- ❌ Add rate limit headers to responses
+- ❌ Implement IP whitelisting
+- ❌ Add endpoint-specific rate limits
 
 ### Phase 4: Advanced Features (Future)
-- ✅ Cache warming for critical data
-- ✅ Two-level caching (Redis + in-memory)
-- ✅ Cache compression for large objects
-- ✅ Rate limit exemptions for admin users
-- ✅ Dynamic rate limit adjustment
-- ✅ Cache analytics and usage patterns
+- ❌ Cache warming for critical data
+- ❌ Two-level caching (Redis + in-memory)
+- ❌ Cache compression for large objects
+- ❌ Rate limit exemptions for admin users
+- ❌ Dynamic rate limit adjustment
+- ❌ Cache analytics and usage patterns
 
 ## Configuration