replace Redis with an embedded SQLite string->string KV store (group commit, in-tx events, SQL search)

internal/config/config.go

@@ -19,8 +19,8 @@ type Config struct {
 	BaseURL        string // Base URL for stable service discovery
 	PublicURL      string // Browser-facing URL for the service-bar nav; overrides BaseURL when set (e.g. a debug-direct port with no Caddy in front)
 
-	// Redis configuration
-	RedisPort int // Redis port (default: 6379)
+	// Storage configuration
+	DBPathOverride string // META_CORE_DB_PATH; empty = <MetaCorePath>/db/meta-core.db
 
 	// HTTP API configuration
 	HTTPPort int    // HTTP API port (default: 9000)
@@ -60,7 +60,7 @@ func Load() *Config {
 		APIPort:                getEnvInt("API_PORT", 8180),
 		BaseURL:                getEnv("BASE_URL", ""),
 		PublicURL:              getEnv("META_CORE_PUBLIC_URL", ""),
-		RedisPort:              getEnvInt("REDIS_PORT", 6379),
+		DBPathOverride:         getEnv("META_CORE_DB_PATH", ""),
 		HTTPPort:               getEnvInt("META_CORE_HTTP_PORT", 9000),
 		HTTPHost:               getEnv("META_CORE_HTTP_HOST", "0.0.0.0"),
 		HealthCheckIntervalMS:  getEnvInt("HEALTH_CHECK_INTERVAL_MS", 5000),
@@ -83,16 +83,20 @@ func Load() *Config {
 	return cfg
 }
 
-// LockFilePath returns the path to the Redis-volume mutex. Held by
+// LockFilePath returns the path to the database-volume mutex (one meta-core
+// per database file). Held by
 // docker/leader-election.sh; nothing reads it, and it is NOT service
 // discovery — see docs/project-architecture/beacon-v2.md.
 func (c *Config) LockFilePath() string {
 	return c.MetaCorePath + "/locks/kv-leader.lock"
 }
 
-// RedisDataDir returns the path to Redis data directory
-func (c *Config) RedisDataDir() string {
-	return c.MetaCorePath + "/db/redis"
+// DBPath returns the path of meta-core's SQLite database file.
+func (c *Config) DBPath() string {
+	if c.DBPathOverride != "" {
+		return c.DBPathOverride
+	}
+	return c.MetaCorePath + "/db/meta-core.db"
 }
 
 // MountsFilePath returns the path to the mounts configuration file