v0.3.4 - Implement secure relay private key storage

- Add relay_seckey table for secure private key storage
- Implement store_relay_private_key() and get_relay_private_key() functions
- Remove relay private key from public configuration events (kind 33334)
- Update first-time startup sequence to store keys securely after DB init
- Add proper validation and error handling for private key operations
- Fix timing issue where private key storage was attempted before DB initialization
- Security improvement: relay private keys no longer exposed in public events

src/main.c

@@ -3227,7 +3227,7 @@ int main(int argc, char* argv[]) {
             return 1;
         }
         
-        // Run first-time startup sequence (generates keys, creates database, etc.)
+        // Run first-time startup sequence (generates keys, sets up database path, but doesn't store private key yet)
         if (first_time_startup_sequence(&cli_options) != 0) {
             log_error("Failed to complete first-time startup sequence");
             cleanup_configuration_system();
@@ -3243,6 +3243,23 @@ int main(int argc, char* argv[]) {
             return 1;
         }
         
+        // Now that database is available, store the relay private key securely
+        const char* relay_privkey = get_temp_relay_private_key();
+        if (relay_privkey) {
+            if (store_relay_private_key(relay_privkey) != 0) {
+                log_error("Failed to store relay private key securely after database initialization");
+                cleanup_configuration_system();
+                nostr_cleanup();
+                return 1;
+            }
+            log_success("Relay private key stored securely in database");
+        } else {
+            log_error("Relay private key not available from first-time startup");
+            cleanup_configuration_system();
+            nostr_cleanup();
+            return 1;
+        }
+        
         // Retry storing the configuration event now that database is initialized
         if (retry_store_initial_config_event() != 0) {
             log_warning("Failed to store initial configuration event after database init");