feat(api): add backend

routes and WebSockets

db/init.sql

@@ -6,7 +6,7 @@ CREATE EXTENSION IF NOT EXISTS timescaledb;
 -- Create audio data table
 CREATE TABLE IF NOT EXISTS audio_data (
     time TIMESTAMPTZ NOT NULL,
-    rms_db REAL CHECK (rms_db >= -40.0 AND rms_db <= 80.0),
+    rms_db REAL CHECK (rms_db >= -50.0 AND rms_db <= 0.0),
     frequency_hz INTEGER CHECK (frequency_hz >= 100 AND frequency_hz <= 8000),
     is_silence BOOLEAN NOT NULL DEFAULT FALSE
 );