feat: Production readiness improvements for WHOOSH council formation

Major security, observability, and configuration improvements:

## Security Hardening
- Implemented configurable CORS (no more wildcards)
- Added comprehensive auth middleware for admin endpoints
- Enhanced webhook HMAC validation
- Added input validation and rate limiting
- Security headers and CSP policies

## Configuration Management
- Made N8N webhook URL configurable (WHOOSH_N8N_BASE_URL)
- Replaced all hardcoded endpoints with environment variables
- Added feature flags for LLM vs heuristic composition
- Gitea fetch hardening with EAGER_FILTER and FULL_RESCAN options

## API Completeness
- Implemented GetCouncilComposition function
- Added GET /api/v1/councils/{id} endpoint
- Council artifacts API (POST/GET /api/v1/councils/{id}/artifacts)
- /admin/health/details endpoint with component status
- Database lookup for repository URLs (no hardcoded fallbacks)

## Observability & Performance
- Added OpenTelemetry distributed tracing with goal/pulse correlation
- Performance optimization database indexes
- Comprehensive health monitoring
- Enhanced logging and error handling

## Infrastructure
- Production-ready P2P discovery (replaces mock implementation)
- Removed unused Redis configuration
- Enhanced Docker Swarm integration
- Added migration files for performance indexes

## Code Quality
- Comprehensive input validation
- Graceful error handling and failsafe fallbacks
- Backwards compatibility maintained
- Following security best practices

🤖 Generated with [Claude Code](https://claude.ai/code)

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

vendor/github.com/nats-io/nats.go/go_test.mod

@@ -0,0 +1,23 @@
+module github.com/nats-io/nats.go
+
+go 1.19
+
+require (
+	github.com/golang/protobuf v1.4.2
+	github.com/klauspost/compress v1.17.8
+	github.com/nats-io/jwt v1.2.2
+	github.com/nats-io/nats-server/v2 v2.10.16
+	github.com/nats-io/nkeys v0.4.7
+	github.com/nats-io/nuid v1.0.1
+	go.uber.org/goleak v1.3.0
+	golang.org/x/text v0.15.0
+	google.golang.org/protobuf v1.23.0
+)
+
+require (
+	github.com/minio/highwayhash v1.0.2 // indirect
+	github.com/nats-io/jwt/v2 v2.5.7 // indirect
+	golang.org/x/crypto v0.23.0 // indirect
+	golang.org/x/sys v0.20.0 // indirect
+	golang.org/x/time v0.5.0 // indirect
+)