refactor: move pipeline to .woodpecker/ directory

Use Woodpecker's default directory-based pipeline discovery.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.woodpecker/build.yaml

@@ -0,0 +1,43 @@
+when:
+  branch: [main, dev]
+  event: push
+
+steps:
+  - name: test
+    image: golang:1.24-alpine
+    commands:
+      - go test ./...
+
+  - name: build
+    image: docker:27-cli
+    environment:
+      DOCKER_HOST: unix:///var/run/docker.sock
+    commands:
+      - docker build -t 10.0.0.3:5000/writekit:${CI_COMMIT_BRANCH} .
+      - docker push 10.0.0.3:5000/writekit:${CI_COMMIT_BRANCH}
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock
+
+  - name: deploy-staging
+    image: alpine
+    when:
+      branch: dev
+    commands:
+      - apk add --no-cache openssh-client
+      - mkdir -p ~/.ssh
+      - cp /mnt/ssh/deploy_key ~/.ssh/id_ed25519
+      - cp /mnt/ssh/known_hosts ~/.ssh/known_hosts
+      - chmod 600 ~/.ssh/id_ed25519
+      - ssh deploy@10.0.0.2 "cd /opt/writekit && docker compose pull writekit-staging && docker compose up -d writekit-staging"
+
+  - name: deploy-prod
+    image: alpine
+    when:
+      branch: main
+    commands:
+      - apk add --no-cache openssh-client
+      - mkdir -p ~/.ssh
+      - cp /mnt/ssh/deploy_key ~/.ssh/id_ed25519
+      - cp /mnt/ssh/known_hosts ~/.ssh/known_hosts
+      - chmod 600 ~/.ssh/id_ed25519
+      - ssh deploy@10.0.0.2 "cd /opt/writekit && docker compose pull writekit-prod && docker compose up -d writekit-prod"