feat: add Woodpecker CI + Gitea deployment templates

- .woodpecker.yml: full pipeline template (install → lint-fix → lint → test → deploy)
- scripts/setup-project.sh: one-command VPS setup (user, dir, deploy, sudoers, systemd, nginx)
- scripts/deploy.sh: deploy script template (rsync + npm ci + systemctl + health check)
- scripts/ci-lint-fix.sh: ESLint auto-fix with [CI SKIP] commit-back
- docs/ci-cd.md: complete CI/CD documentation and troubleshooting
- .env.example: added WOODPECKER_TOKEN
- DOCS.md: added CI/CD section

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.woodpecker.yml

@@ -1,6 +1,69 @@
+# Woodpecker CI pipeline template.
+#
+# Runs on the local backend — image: bash specifies the shell.
+# Triggers on push to main branch.
+#
+# Flow: install → lint-fix (optional) → lint + test → deploy
+#
+# Secrets (add in Woodpecker UI → repo or global settings):
+#   gitea_token  — Gitea access token (for lint-fix auto-commit back)
+#
+# Deploy setup (one-time, as root on VPS):
+#   1. Create deploy script:
+#      cp scripts/deploy.sh /usr/local/bin/deploy-<project-name>
+#      chmod 755 /usr/local/bin/deploy-<project-name>
+#      chown root:root /usr/local/bin/deploy-<project-name>
+#
+#   2. Find Woodpecker agent user:
+#      ps -o user= -p $(pgrep woodpecker-agent)
+#
+#   3. Set up sudoers (replace AGENT_USER and script name):
+#      echo 'AGENT_USER ALL=(root) NOPASSWD: /usr/local/bin/deploy-<project-name> *' \
+#        > /etc/sudoers.d/woodpecker-deploy
+#      chmod 0440 /etc/sudoers.d/woodpecker-deploy
+#      visudo -cf /etc/sudoers.d/woodpecker-deploy
+
+when:
+  - event: push
+    branch: main
+
 steps:
+  - name: install
+    image: bash
+    commands:
+      - npm ci
+
+  # Optional: auto-fix lint issues and commit back.
+  # Requires gitea_token secret. Remove this step if not needed.
+  # The [CI SKIP] in commit message prevents infinite loops.
+  #
+  # - name: lint-fix
+  #   image: bash
+  #   environment:
+  #     GITEA_TOKEN:
+  #       from_secret: gitea_token
+  #   commands:
+  #     - bash scripts/ci-lint-fix.sh
+  #   depends_on: [install]
+
+  - name: lint
+    image: bash
+    commands:
+      - npx eslint .
+    depends_on: [install]
+
   - name: test
     image: bash
     commands:
-      - echo "Hello from Woodpecker CI!"
-      - echo "Build successful"
+      - npm test
+    depends_on: [install]
+
+  # Uncomment when deploy script is set up on VPS:
+  #
+  # - name: deploy
+  #   image: bash
+  #   environment:
+  #     CI: "true"
+  #   commands:
+  #     - sudo /usr/local/bin/deploy-<project-name> "${CI_WORKSPACE:-.}"
+  #   depends_on: [lint, test]