chore(backend): remove LocalDateTime usage, replaced with Instant

src/main/resources/application-local.properties

@@ -1,6 +1,6 @@
 spring.docker.compose.file=docker-compose.dev.yml
 
-media.temp.inputs=./video/inputs
+media.temp.inputs=./videos/inputs
 media.temp.outputs=./videos/outputs
 media.users=${MEDIA_DATA}
 media.streams=${STREAM_DATA}

src/main/resources/application.properties

@@ -31,4 +31,7 @@ media.users=/app/media/
 media.streams=/app/stream/
 
 ## Server Configuration
-server.servlet.session.timeout=30m
+server.servlet.session.timeout=30m
+
+# Serialize Instant as ISO-8601 UTC string (not epoch seconds)
+spring.jackson.serialization.write-dates-as-timestamps=false

src/main/resources/db/schema.sql

@@ -10,7 +10,7 @@ CREATE TABLE IF NOT EXISTS users (
     name VARCHAR(100) NOT NULL,
     profile_picture_url VARCHAR(255),
     role INTEGER DEFAULT 0,
-    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    created_at TIMESTAMPTZ DEFAULT NOW(),
     stream_key VARCHAR(64) NOT NULL UNIQUE
 );
 
@@ -29,7 +29,7 @@ CREATE TABLE IF NOT EXISTS clips (
     user_id BIGINT NOT NULL,
     title VARCHAR(255) NOT NULL,
     description TEXT,
-    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    created_at TIMESTAMPTZ DEFAULT NOW(),
     width INTEGER NOT NULL,
     height INTEGER NOT NULL,
     fps FLOAT NOT NULL,