feat: structure view in dashboard and settings persistence

- Add GET /api/claude/sessions/{session_id}/builder API for structure view
- Load builder session tags and snippets by Claude session ID
- Implement structure view in dashboard: shows tag selections and snippet details
- Add LoadSettings to persist LLM config changes across restarts
- Settings are now loaded from database on startup

Co-Authored-By: Claude <noreply@anthropic.com>

internal/db/db.go

@@ -109,6 +109,36 @@ func AutoMigrate() error {
 	return nil
 }
 
+// LoadSettings loads persisted settings from the database into config
+func LoadSettings(cfg *config.Config) {
+	// Create settings table if not exists
+	DB.Exec(`CREATE TABLE IF NOT EXISTS settings (
+		key_name varchar(64) NOT NULL PRIMARY KEY,
+		value text NOT NULL
+	) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4`)
+
+	rows, err := DB.Query("SELECT key_name, value FROM settings")
+	if err != nil {
+		return
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		var key, value string
+		if err := rows.Scan(&key, &value); err != nil {
+			continue
+		}
+		switch key {
+		case "llm_api_base_url":
+			cfg.LLMAPIBaseURL = value
+		case "llm_api_key":
+			cfg.LLMAPIKey = value
+		case "llm_model_name":
+			cfg.LLMModelName = value
+		}
+	}
+}
+
 // EnsurePromptsTable creates the prompts table if it doesn't exist (for dev environments)
 func EnsurePromptsTable() {
 	_, err := DB.Exec(`CREATE TABLE IF NOT EXISTS prompts (