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/doc.go

@@ -0,0 +1,34 @@
+// Package pgconn is a low-level PostgreSQL database driver.
+/*
+pgconn provides lower level access to a PostgreSQL connection than a database/sql or pgx connection. It operates at
+nearly the same level is the C library libpq.
+
+Establishing a Connection
+
+Use Connect to establish a connection. It accepts a connection string in URL or DSN and will read the environment for
+libpq style environment variables.
+
+Executing a Query
+
+ExecParams and ExecPrepared execute a single query. They return readers that iterate over each row. The Read method
+reads all rows into memory.
+
+Executing Multiple Queries in a Single Round Trip
+
+Exec and ExecBatch can execute multiple queries in a single round trip. They return readers that iterate over each query
+result. The ReadAll method reads all query results into memory.
+
+Pipeline Mode
+
+Pipeline mode allows sending queries without having read the results of previously sent queries. It allows
+control of exactly how many and when network round trips occur.
+
+Context Support
+
+All potentially blocking operations take a context.Context. If a context is canceled while the method is in progress the
+method immediately returns. In most circumstances, this will close the underlying connection.
+
+The CancelRequest method may be used to request the PostgreSQL server cancel an in-progress query without forcing the
+client to abort.
+*/
+package pgconn