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/lib/pq/notice.go

@@ -0,0 +1,72 @@
+//go:build go1.10
+// +build go1.10
+
+package pq
+
+import (
+	"context"
+	"database/sql/driver"
+)
+
+// NoticeHandler returns the notice handler on the given connection, if any. A
+// runtime panic occurs if c is not a pq connection. This is rarely used
+// directly, use ConnectorNoticeHandler and ConnectorWithNoticeHandler instead.
+func NoticeHandler(c driver.Conn) func(*Error) {
+	return c.(*conn).noticeHandler
+}
+
+// SetNoticeHandler sets the given notice handler on the given connection. A
+// runtime panic occurs if c is not a pq connection. A nil handler may be used
+// to unset it. This is rarely used directly, use ConnectorNoticeHandler and
+// ConnectorWithNoticeHandler instead.
+//
+// Note: Notice handlers are executed synchronously by pq meaning commands
+// won't continue to be processed until the handler returns.
+func SetNoticeHandler(c driver.Conn, handler func(*Error)) {
+	c.(*conn).noticeHandler = handler
+}
+
+// NoticeHandlerConnector wraps a regular connector and sets a notice handler
+// on it.
+type NoticeHandlerConnector struct {
+	driver.Connector
+	noticeHandler func(*Error)
+}
+
+// Connect calls the underlying connector's connect method and then sets the
+// notice handler.
+func (n *NoticeHandlerConnector) Connect(ctx context.Context) (driver.Conn, error) {
+	c, err := n.Connector.Connect(ctx)
+	if err == nil {
+		SetNoticeHandler(c, n.noticeHandler)
+	}
+	return c, err
+}
+
+// ConnectorNoticeHandler returns the currently set notice handler, if any. If
+// the given connector is not a result of ConnectorWithNoticeHandler, nil is
+// returned.
+func ConnectorNoticeHandler(c driver.Connector) func(*Error) {
+	if c, ok := c.(*NoticeHandlerConnector); ok {
+		return c.noticeHandler
+	}
+	return nil
+}
+
+// ConnectorWithNoticeHandler creates or sets the given handler for the given
+// connector. If the given connector is a result of calling this function
+// previously, it is simply set on the given connector and returned. Otherwise,
+// this returns a new connector wrapping the given one and setting the notice
+// handler. A nil notice handler may be used to unset it.
+//
+// The returned connector is intended to be used with database/sql.OpenDB.
+//
+// Note: Notice handlers are executed synchronously by pq meaning commands
+// won't continue to be processed until the handler returns.
+func ConnectorWithNoticeHandler(c driver.Connector, handler func(*Error)) *NoticeHandlerConnector {
+	if c, ok := c.(*NoticeHandlerConnector); ok {
+		c.noticeHandler = handler
+		return c
+	}
+	return &NoticeHandlerConnector{Connector: c, noticeHandler: handler}
+}