feat(db): add V7 deployment orchestration migration

Adds target_state, deployment_strategy, replica_states (JSONB), and
deploy_stage columns to the deployments table with backfill logic.

cameleer3-server-app/src/main/resources/db/migration/V7__deployment_orchestration.sql

@@ -0,0 +1,12 @@
+-- Deployment orchestration: status model, replicas, strategies, progress tracking
+
+ALTER TABLE deployments ADD COLUMN target_state VARCHAR(20) NOT NULL DEFAULT 'RUNNING';
+ALTER TABLE deployments ADD COLUMN deployment_strategy VARCHAR(20) NOT NULL DEFAULT 'BLUE_GREEN';
+ALTER TABLE deployments ADD COLUMN replica_states JSONB NOT NULL DEFAULT '[]';
+ALTER TABLE deployments ADD COLUMN deploy_stage VARCHAR(30);
+
+-- Backfill existing deployments
+UPDATE deployments SET target_state = CASE
+    WHEN status = 'STOPPED' THEN 'STOPPED'
+    ELSE 'RUNNING'
+END;