feat: add database migrations for environments, apps, deployments

src/main/resources/db/migration/V009__create_deployments.sql

@@ -0,0 +1,16 @@
+CREATE TABLE deployments (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    app_id UUID NOT NULL REFERENCES apps(id) ON DELETE CASCADE,
+    version INTEGER NOT NULL,
+    image_ref VARCHAR(500) NOT NULL,
+    desired_status VARCHAR(20) NOT NULL DEFAULT 'RUNNING',
+    observed_status VARCHAR(20) NOT NULL DEFAULT 'BUILDING',
+    orchestrator_metadata JSONB DEFAULT '{}',
+    error_message TEXT,
+    deployed_at TIMESTAMPTZ,
+    stopped_at TIMESTAMPTZ,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    UNIQUE(app_id, version)
+);
+
+CREATE INDEX idx_deployments_app_id ON deployments(app_id);