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/pgservicefile/pgservicefile.go

@@ -0,0 +1,79 @@
+// Package pgservicefile is a parser for PostgreSQL service files (e.g. .pg_service.conf).
+package pgservicefile
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+)
+
+type Service struct {
+	Name     string
+	Settings map[string]string
+}
+
+type Servicefile struct {
+	Services       []*Service
+	servicesByName map[string]*Service
+}
+
+// GetService returns the named service.
+func (sf *Servicefile) GetService(name string) (*Service, error) {
+	service, present := sf.servicesByName[name]
+	if !present {
+		return nil, errors.New("not found")
+	}
+	return service, nil
+}
+
+// ReadServicefile reads the file at path and parses it into a Servicefile.
+func ReadServicefile(path string) (*Servicefile, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	return ParseServicefile(f)
+}
+
+// ParseServicefile reads r and parses it into a Servicefile.
+func ParseServicefile(r io.Reader) (*Servicefile, error) {
+	servicefile := &Servicefile{}
+
+	var service *Service
+	scanner := bufio.NewScanner(r)
+	lineNum := 0
+	for scanner.Scan() {
+		lineNum += 1
+		line := scanner.Text()
+		line = strings.TrimSpace(line)
+
+		if line == "" || strings.HasPrefix(line, "#") {
+			// ignore comments and empty lines
+		} else if strings.HasPrefix(line, "[") && strings.HasSuffix(line, "]") {
+			service = &Service{Name: line[1 : len(line)-1], Settings: make(map[string]string)}
+			servicefile.Services = append(servicefile.Services, service)
+		} else {
+			parts := strings.SplitN(line, "=", 2)
+			if len(parts) != 2 {
+				return nil, fmt.Errorf("unable to parse line %d", lineNum)
+			}
+
+			key := strings.TrimSpace(parts[0])
+			value := strings.TrimSpace(parts[1])
+
+			service.Settings[key] = value
+		}
+	}
+
+	servicefile.servicesByName = make(map[string]*Service, len(servicefile.Services))
+	for _, service := range servicefile.Services {
+		servicefile.servicesByName[service.Name] = service
+	}
+
+	return servicefile, scanner.Err()
+}