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/rs/zerolog/ctx.go

@@ -0,0 +1,52 @@
+package zerolog
+
+import (
+	"context"
+)
+
+var disabledLogger *Logger
+
+func init() {
+	SetGlobalLevel(TraceLevel)
+	l := Nop()
+	disabledLogger = &l
+}
+
+type ctxKey struct{}
+
+// WithContext returns a copy of ctx with the receiver attached. The Logger
+// attached to the provided Context (if any) will not be effected.  If the
+// receiver's log level is Disabled it will only be attached to the returned
+// Context if the provided Context has a previously attached Logger. If the
+// provided Context has no attached Logger, a Disabled Logger will not be
+// attached.
+//
+// Note: to modify the existing Logger attached to a Context (instead of
+// replacing it in a new Context), use UpdateContext with the following
+// notation:
+//
+//     ctx := r.Context()
+//     l := zerolog.Ctx(ctx)
+//     l.UpdateContext(func(c Context) Context {
+//         return c.Str("bar", "baz")
+//     })
+//
+func (l Logger) WithContext(ctx context.Context) context.Context {
+	if _, ok := ctx.Value(ctxKey{}).(*Logger); !ok && l.level == Disabled {
+		// Do not store disabled logger.
+		return ctx
+	}
+	return context.WithValue(ctx, ctxKey{}, &l)
+}
+
+// Ctx returns the Logger associated with the ctx. If no logger
+// is associated, DefaultContextLogger is returned, unless DefaultContextLogger
+// is nil, in which case a disabled logger is returned.
+func Ctx(ctx context.Context) *Logger {
+	if l, ok := ctx.Value(ctxKey{}).(*Logger); ok {
+		return l
+	} else if l = DefaultContextLogger; l != nil {
+		return l
+	}
+	return disabledLogger
+}