fix: CI migration workflow — install Docker before migration runner

Add docker.io + DOCKER_HOST (tcp://localhost:2375) to migration workflow.
Ensures Node + Docker available before migration action executes.
Aligns with build.yaml environment setup.

.gitea/workflows/migrate.yaml

@@ -12,16 +12,17 @@ env:
   DB_PORT: "5432"
   DB_NAME: memory
   MIGRATIONS_DIR: crates/mem-store/migrations
+  DOCKER_HOST: tcp://localhost:2375
 
 jobs:
   migrate:
     name: Run Migrations
     runs-on: rust
     steps:
-      - name: Install Node.js and psql
+      - name: Install Node.js, Docker, and psql
         run: |
           apt-get update
-          apt-get install -y nodejs postgresql-client
+          apt-get install -y nodejs docker.io postgresql-client
 
       - name: Checkout code
         uses: actions/checkout@v4