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/pgconn/defaults.go

@@ -0,0 +1,63 @@
+//go:build !windows
+// +build !windows
+
+package pgconn
+
+import (
+	"os"
+	"os/user"
+	"path/filepath"
+)
+
+func defaultSettings() map[string]string {
+	settings := make(map[string]string)
+
+	settings["host"] = defaultHost()
+	settings["port"] = "5432"
+
+	// Default to the OS user name. Purposely ignoring err getting user name from
+	// OS. The client application will simply have to specify the user in that
+	// case (which they typically will be doing anyway).
+	user, err := user.Current()
+	if err == nil {
+		settings["user"] = user.Username
+		settings["passfile"] = filepath.Join(user.HomeDir, ".pgpass")
+		settings["servicefile"] = filepath.Join(user.HomeDir, ".pg_service.conf")
+		sslcert := filepath.Join(user.HomeDir, ".postgresql", "postgresql.crt")
+		sslkey := filepath.Join(user.HomeDir, ".postgresql", "postgresql.key")
+		if _, err := os.Stat(sslcert); err == nil {
+			if _, err := os.Stat(sslkey); err == nil {
+				// Both the cert and key must be present to use them, or do not use either
+				settings["sslcert"] = sslcert
+				settings["sslkey"] = sslkey
+			}
+		}
+		sslrootcert := filepath.Join(user.HomeDir, ".postgresql", "root.crt")
+		if _, err := os.Stat(sslrootcert); err == nil {
+			settings["sslrootcert"] = sslrootcert
+		}
+	}
+
+	settings["target_session_attrs"] = "any"
+
+	return settings
+}
+
+// defaultHost attempts to mimic libpq's default host. libpq uses the default unix socket location on *nix and localhost
+// on Windows. The default socket location is compiled into libpq. Since pgx does not have access to that default it
+// checks the existence of common locations.
+func defaultHost() string {
+	candidatePaths := []string{
+		"/var/run/postgresql", // Debian
+		"/private/tmp",        // OSX - homebrew
+		"/tmp",                // standard PostgreSQL
+	}
+
+	for _, path := range candidatePaths {
+		if _, err := os.Stat(path); err == nil {
+			return path
+		}
+	}
+
+	return "localhost"
+}