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/internal/stmtcache/lru_cache.go

@@ -0,0 +1,108 @@
+package stmtcache
+
+import (
+	"container/list"
+
+	"github.com/jackc/pgx/v5/pgconn"
+)
+
+// LRUCache implements Cache with a Least Recently Used (LRU) cache.
+type LRUCache struct {
+	cap          int
+	m            map[string]*list.Element
+	l            *list.List
+	invalidStmts []*pgconn.StatementDescription
+}
+
+// NewLRUCache creates a new LRUCache. cap is the maximum size of the cache.
+func NewLRUCache(cap int) *LRUCache {
+	return &LRUCache{
+		cap: cap,
+		m:   make(map[string]*list.Element),
+		l:   list.New(),
+	}
+}
+
+// Get returns the statement description for sql. Returns nil if not found.
+func (c *LRUCache) Get(key string) *pgconn.StatementDescription {
+	if el, ok := c.m[key]; ok {
+		c.l.MoveToFront(el)
+		return el.Value.(*pgconn.StatementDescription)
+	}
+
+	return nil
+
+}
+
+// Put stores sd in the cache. Put panics if sd.SQL is "". Put does nothing if sd.SQL already exists in the cache or
+// sd.SQL has been invalidated and HandleInvalidated has not been called yet.
+func (c *LRUCache) Put(sd *pgconn.StatementDescription) {
+	if sd.SQL == "" {
+		panic("cannot store statement description with empty SQL")
+	}
+
+	if _, present := c.m[sd.SQL]; present {
+		return
+	}
+
+	// The statement may have been invalidated but not yet handled. Do not readd it to the cache.
+	for _, invalidSD := range c.invalidStmts {
+		if invalidSD.SQL == sd.SQL {
+			return
+		}
+	}
+
+	if c.l.Len() == c.cap {
+		c.invalidateOldest()
+	}
+
+	el := c.l.PushFront(sd)
+	c.m[sd.SQL] = el
+}
+
+// Invalidate invalidates statement description identified by sql. Does nothing if not found.
+func (c *LRUCache) Invalidate(sql string) {
+	if el, ok := c.m[sql]; ok {
+		delete(c.m, sql)
+		c.invalidStmts = append(c.invalidStmts, el.Value.(*pgconn.StatementDescription))
+		c.l.Remove(el)
+	}
+}
+
+// InvalidateAll invalidates all statement descriptions.
+func (c *LRUCache) InvalidateAll() {
+	el := c.l.Front()
+	for el != nil {
+		c.invalidStmts = append(c.invalidStmts, el.Value.(*pgconn.StatementDescription))
+		el = el.Next()
+	}
+
+	c.m = make(map[string]*list.Element)
+	c.l = list.New()
+}
+
+// HandleInvalidated returns a slice of all statement descriptions invalidated since the last call to HandleInvalidated.
+// Typically, the caller will then deallocate them.
+func (c *LRUCache) HandleInvalidated() []*pgconn.StatementDescription {
+	invalidStmts := c.invalidStmts
+	c.invalidStmts = nil
+	return invalidStmts
+}
+
+// Len returns the number of cached prepared statement descriptions.
+func (c *LRUCache) Len() int {
+	return c.l.Len()
+}
+
+// Cap returns the maximum number of cached prepared statement descriptions.
+func (c *LRUCache) Cap() int {
+	return c.cap
+}
+
+func (c *LRUCache) invalidateOldest() {
+	oldest := c.l.Back()
+	sd := oldest.Value.(*pgconn.StatementDescription)
+	c.invalidStmts = append(c.invalidStmts, sd)
+	delete(c.m, sd.SQL)
+	c.l.Remove(oldest)
+}

vendor/github.com/jackc/pgx/v5/internal/stmtcache/stmtcache.go

@@ -0,0 +1,40 @@
+// Package stmtcache is a cache for statement descriptions.
+package stmtcache
+
+import (
+	"crypto/sha256"
+	"encoding/hex"
+
+	"github.com/jackc/pgx/v5/pgconn"
+)
+
+// StatementName returns a statement name that will be stable for sql across multiple connections and program
+// executions.
+func StatementName(sql string) string {
+	digest := sha256.Sum256([]byte(sql))
+	return "stmtcache_" + hex.EncodeToString(digest[0:24])
+}
+
+// Cache caches statement descriptions.
+type Cache interface {
+	// Get returns the statement description for sql. Returns nil if not found.
+	Get(sql string) *pgconn.StatementDescription
+
+	// Put stores sd in the cache. Put panics if sd.SQL is "". Put does nothing if sd.SQL already exists in the cache.
+	Put(sd *pgconn.StatementDescription)
+
+	// Invalidate invalidates statement description identified by sql. Does nothing if not found.
+	Invalidate(sql string)
+
+	// InvalidateAll invalidates all statement descriptions.
+	InvalidateAll()
+
+	// HandleInvalidated returns a slice of all statement descriptions invalidated since the last call to HandleInvalidated.
+	HandleInvalidated() []*pgconn.StatementDescription
+
+	// Len returns the number of cached prepared statement descriptions.
+	Len() int
+
+	// Cap returns the maximum number of cached prepared statement descriptions.
+	Cap() int
+}

vendor/github.com/jackc/pgx/v5/internal/stmtcache/unlimited_cache.go

@@ -0,0 +1,71 @@
+package stmtcache
+
+import (
+	"math"
+
+	"github.com/jackc/pgx/v5/pgconn"
+)
+
+// UnlimitedCache implements Cache with no capacity limit.
+type UnlimitedCache struct {
+	m            map[string]*pgconn.StatementDescription
+	invalidStmts []*pgconn.StatementDescription
+}
+
+// NewUnlimitedCache creates a new UnlimitedCache.
+func NewUnlimitedCache() *UnlimitedCache {
+	return &UnlimitedCache{
+		m: make(map[string]*pgconn.StatementDescription),
+	}
+}
+
+// Get returns the statement description for sql. Returns nil if not found.
+func (c *UnlimitedCache) Get(sql string) *pgconn.StatementDescription {
+	return c.m[sql]
+}
+
+// Put stores sd in the cache. Put panics if sd.SQL is "". Put does nothing if sd.SQL already exists in the cache.
+func (c *UnlimitedCache) Put(sd *pgconn.StatementDescription) {
+	if sd.SQL == "" {
+		panic("cannot store statement description with empty SQL")
+	}
+
+	if _, present := c.m[sd.SQL]; present {
+		return
+	}
+
+	c.m[sd.SQL] = sd
+}
+
+// Invalidate invalidates statement description identified by sql. Does nothing if not found.
+func (c *UnlimitedCache) Invalidate(sql string) {
+	if sd, ok := c.m[sql]; ok {
+		delete(c.m, sql)
+		c.invalidStmts = append(c.invalidStmts, sd)
+	}
+}
+
+// InvalidateAll invalidates all statement descriptions.
+func (c *UnlimitedCache) InvalidateAll() {
+	for _, sd := range c.m {
+		c.invalidStmts = append(c.invalidStmts, sd)
+	}
+
+	c.m = make(map[string]*pgconn.StatementDescription)
+}
+
+func (c *UnlimitedCache) HandleInvalidated() []*pgconn.StatementDescription {
+	invalidStmts := c.invalidStmts
+	c.invalidStmts = nil
+	return invalidStmts
+}
+
+// Len returns the number of cached prepared statement descriptions.
+func (c *UnlimitedCache) Len() int {
+	return len(c.m)
+}
+
+// Cap returns the maximum number of cached prepared statement descriptions.
+func (c *UnlimitedCache) Cap() int {
+	return math.MaxInt
+}