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/jackc/pgx/v5/pgproto3/copy_data.go

@@ -0,0 +1,62 @@
+package pgproto3
+
+import (
+	"encoding/hex"
+	"encoding/json"
+
+	"github.com/jackc/pgx/v5/internal/pgio"
+)
+
+type CopyData struct {
+	Data []byte
+}
+
+// Backend identifies this message as sendable by the PostgreSQL backend.
+func (*CopyData) Backend() {}
+
+// Frontend identifies this message as sendable by a PostgreSQL frontend.
+func (*CopyData) Frontend() {}
+
+// Decode decodes src into dst. src must contain the complete message with the exception of the initial 1 byte message
+// type identifier and 4 byte message length.
+func (dst *CopyData) Decode(src []byte) error {
+	dst.Data = src
+	return nil
+}
+
+// Encode encodes src into dst. dst will include the 1 byte message type identifier and the 4 byte message length.
+func (src *CopyData) Encode(dst []byte) []byte {
+	dst = append(dst, 'd')
+	dst = pgio.AppendInt32(dst, int32(4+len(src.Data)))
+	dst = append(dst, src.Data...)
+	return dst
+}
+
+// MarshalJSON implements encoding/json.Marshaler.
+func (src CopyData) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Type string
+		Data string
+	}{
+		Type: "CopyData",
+		Data: hex.EncodeToString(src.Data),
+	})
+}
+
+// UnmarshalJSON implements encoding/json.Unmarshaler.
+func (dst *CopyData) UnmarshalJSON(data []byte) error {
+	// Ignore null, like in the main JSON package.
+	if string(data) == "null" {
+		return nil
+	}
+
+	var msg struct {
+		Data string
+	}
+	if err := json.Unmarshal(data, &msg); err != nil {
+		return err
+	}
+
+	dst.Data = []byte(msg.Data)
+	return nil
+}