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/google/uuid/version6.go

@@ -0,0 +1,56 @@
+// Copyright 2023 Google Inc.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package uuid
+
+import "encoding/binary"
+
+// UUID version 6 is a field-compatible version of UUIDv1, reordered for improved DB locality.
+// It is expected that UUIDv6 will primarily be used in contexts where there are existing v1 UUIDs.
+// Systems that do not involve legacy UUIDv1 SHOULD consider using UUIDv7 instead.
+//
+// see https://datatracker.ietf.org/doc/html/draft-peabody-dispatch-new-uuid-format-03#uuidv6
+//
+// NewV6 returns a Version 6 UUID based on the current NodeID and clock
+// sequence, and the current time. If the NodeID has not been set by SetNodeID
+// or SetNodeInterface then it will be set automatically. If the NodeID cannot
+// be set NewV6 set NodeID is random bits automatically . If clock sequence has not been set by
+// SetClockSequence then it will be set automatically. If GetTime fails to
+// return the current NewV6 returns Nil and an error.
+func NewV6() (UUID, error) {
+	var uuid UUID
+	now, seq, err := GetTime()
+	if err != nil {
+		return uuid, err
+	}
+
+	/*
+	    0                   1                   2                   3
+	    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+	   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	   |                           time_high                           |
+	   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	   |           time_mid            |      time_low_and_version     |
+	   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	   |clk_seq_hi_res |  clk_seq_low  |         node (0-1)            |
+	   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	   |                         node (2-5)                            |
+	   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+	*/
+
+	binary.BigEndian.PutUint64(uuid[0:], uint64(now))
+	binary.BigEndian.PutUint16(uuid[8:], seq)
+
+	uuid[6] = 0x60 | (uuid[6] & 0x0F)
+	uuid[8] = 0x80 | (uuid[8] & 0x3F)
+
+	nodeMu.Lock()
+	if nodeID == zeroID {
+		setNodeInterface("")
+	}
+	copy(uuid[10:], nodeID[:])
+	nodeMu.Unlock()
+
+	return uuid, nil
+}