feat: Go backend, enhanced search, new widgets, Docker deploy

Major changes:
- Add Go backend (backend/) with microservices architecture
- Enhanced master-agents-svc: reranker, content-classifier, stealth-crawler,
  proxy-manager, media-search, fastClassifier, language detection
- New web-svc widgets: KnowledgeCard, ProductCard, ProfileCard, VideoCard,
  UnifiedCard, CardGallery, InlineImageGallery, SourcesPanel, RelatedQuestions
- Improved discover-svc with discover-db integration
- Docker deployment improvements (Caddyfile, vendor.sh, BUILD.md)
- Library-svc: project_id schema migration
- Remove deprecated finance-svc and travel-svc
- Localization improvements across services

Made-with: Cursor

backend/pkg/cache/redis.go

@@ -0,0 +1,183 @@
+package cache
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"time"
+
+	"github.com/redis/go-redis/v9"
+)
+
+type RedisCache struct {
+	client *redis.Client
+	prefix string
+}
+
+func NewRedisCache(redisURL, prefix string) (*RedisCache, error) {
+	opts, err := redis.ParseURL(redisURL)
+	if err != nil {
+		return nil, err
+	}
+
+	client := redis.NewClient(opts)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	if err := client.Ping(ctx).Err(); err != nil {
+		return nil, err
+	}
+
+	return &RedisCache{
+		client: client,
+		prefix: prefix,
+	}, nil
+}
+
+func (c *RedisCache) Close() error {
+	return c.client.Close()
+}
+
+func (c *RedisCache) Set(ctx context.Context, key string, value interface{}, ttl time.Duration) error {
+	data, err := json.Marshal(value)
+	if err != nil {
+		return err
+	}
+	return c.client.Set(ctx, c.prefix+":"+key, data, ttl).Err()
+}
+
+func (c *RedisCache) Get(ctx context.Context, key string, dest interface{}) error {
+	data, err := c.client.Get(ctx, c.prefix+":"+key).Bytes()
+	if err != nil {
+		return err
+	}
+	return json.Unmarshal(data, dest)
+}
+
+func (c *RedisCache) Exists(ctx context.Context, key string) (bool, error) {
+	n, err := c.client.Exists(ctx, c.prefix+":"+key).Result()
+	if err != nil {
+		return false, err
+	}
+	return n > 0, nil
+}
+
+func (c *RedisCache) Delete(ctx context.Context, key string) error {
+	return c.client.Del(ctx, c.prefix+":"+key).Err()
+}
+
+func (c *RedisCache) SetJSON(ctx context.Context, key string, value interface{}, ttl time.Duration) error {
+	return c.Set(ctx, key, value, ttl)
+}
+
+func (c *RedisCache) GetJSON(ctx context.Context, key string, dest interface{}) error {
+	return c.Get(ctx, key, dest)
+}
+
+type CacheKey string
+
+const (
+	KeySearchResults   CacheKey = "search"
+	KeyArticleSummary  CacheKey = "summary"
+	KeyDigest          CacheKey = "digest"
+	KeyChatResponse    CacheKey = "chat"
+)
+
+func HashKey(parts ...string) string {
+	combined := ""
+	for _, p := range parts {
+		combined += p + ":"
+	}
+	hash := sha256.Sum256([]byte(combined))
+	return hex.EncodeToString(hash[:16])
+}
+
+func (c *RedisCache) CacheSearch(ctx context.Context, query string, results interface{}, ttl time.Duration) error {
+	key := string(KeySearchResults) + ":" + HashKey(query)
+	return c.Set(ctx, key, results, ttl)
+}
+
+func (c *RedisCache) GetCachedSearch(ctx context.Context, query string, dest interface{}) error {
+	key := string(KeySearchResults) + ":" + HashKey(query)
+	return c.Get(ctx, key, dest)
+}
+
+func (c *RedisCache) CacheArticleSummary(ctx context.Context, url string, events []string, ttl time.Duration) error {
+	key := string(KeyArticleSummary) + ":" + HashKey(url)
+	return c.Set(ctx, key, events, ttl)
+}
+
+func (c *RedisCache) GetCachedArticleSummary(ctx context.Context, url string) ([]string, error) {
+	key := string(KeyArticleSummary) + ":" + HashKey(url)
+	var events []string
+	if err := c.Get(ctx, key, &events); err != nil {
+		return nil, err
+	}
+	return events, nil
+}
+
+func (c *RedisCache) CacheDigest(ctx context.Context, topic, region, title string, digest interface{}, ttl time.Duration) error {
+	key := string(KeyDigest) + ":" + HashKey(topic, region, title)
+	return c.Set(ctx, key, digest, ttl)
+}
+
+func (c *RedisCache) GetCachedDigest(ctx context.Context, topic, region, title string, dest interface{}) error {
+	key := string(KeyDigest) + ":" + HashKey(topic, region, title)
+	return c.Get(ctx, key, dest)
+}
+
+type MemoryCache struct {
+	data map[string]cacheEntry
+}
+
+type cacheEntry struct {
+	value     interface{}
+	expiresAt time.Time
+}
+
+func NewMemoryCache() *MemoryCache {
+	return &MemoryCache{
+		data: make(map[string]cacheEntry),
+	}
+}
+
+func (c *MemoryCache) Set(key string, value interface{}, ttl time.Duration) {
+	c.data[key] = cacheEntry{
+		value:     value,
+		expiresAt: time.Now().Add(ttl),
+	}
+}
+
+func (c *MemoryCache) Get(key string) (interface{}, bool) {
+	entry, ok := c.data[key]
+	if !ok {
+		return nil, false
+	}
+	if time.Now().After(entry.expiresAt) {
+		delete(c.data, key)
+		return nil, false
+	}
+	return entry.value, true
+}
+
+func (c *MemoryCache) Delete(key string) {
+	delete(c.data, key)
+}
+
+func (c *MemoryCache) Clear() {
+	c.data = make(map[string]cacheEntry)
+}
+
+func (c *MemoryCache) Cleanup() int {
+	count := 0
+	now := time.Now()
+	for k, v := range c.data {
+		if now.After(v.expiresAt) {
+			delete(c.data, k)
+			count++
+		}
+	}
+	return count
+}