feat: migrate citation to Plugin API v2

.github/workflows/plugin-api-v2.yml

@@ -0,0 +1,28 @@
+name: plugin-api-v2
+
+on:
+  pull_request:
+  push:
+    branches:
+      - main
+
+permissions:
+  contents: read
+
+jobs:
+  contract:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/checkout@v4
+        with:
+          repository: akashic-plugins/plugin-contracts
+          ref: 24543445c7b99ca63fcd90b5828f754a148b184c
+          path: .plugin-contracts
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.13"
+      - name: Check Plugin API v2
+        env:
+          PYTHONPATH: .plugin-contracts
+        run: python -m akashic_plugin_contracts check plugin.py

plugin.py

@@ -92,6 +92,7 @@ async def run(self, frame: Any) -> Any:
 
 
 class CitationPlugin(Plugin):
+    api_version = 2
     name = "citation"
     version = "1.0.0"