fix: resolve all ruff linting errors and add lint CI check

- Fix ambiguous fullwidth characters (commas, parentheses) in strings and comments
- Replace Chinese comments with English equivalents
- Fix unused imports with proper noqa annotations for intentional imports
- Fix bare except clauses with specific exception types
- Fix redefined variables and undefined names
- Add ruff noqa annotations for generated protobuf files
- Add lint and format check to GitHub Actions CI pipeline

demo.ipynb

@@ -22,7 +22,8 @@
     "! uv pip install leann --no-deps\n",
     "# For Colab environment, we need to set some environment variables\n",
     "import os\n",
-    "os.environ['LEANN_LOG_LEVEL'] = 'INFO'  # Enable more detailed logging"
+    "\n",
+    "os.environ[\"LEANN_LOG_LEVEL\"] = \"INFO\"  # Enable more detailed logging"
    ]
   },
   {
@@ -32,6 +33,7 @@
    "outputs": [],
    "source": [
     "from pathlib import Path\n",
+    "\n",
     "INDEX_DIR = Path(\"./\").resolve()\n",
     "INDEX_PATH = str(INDEX_DIR / \"demo.leann\")"
    ]
@@ -111,9 +113,12 @@
    ],
    "source": [
     "from leann.api import LeannBuilder\n",
+    "\n",
     "builder = LeannBuilder(backend_name=\"hnsw\")\n",
     "builder.add_text(\"C# is a powerful programming language and it is good at game development\")\n",
-    "builder.add_text(\"Python is a powerful programming language and it is good at machine learning tasks\")\n",
+    "builder.add_text(\n",
+    "    \"Python is a powerful programming language and it is good at machine learning tasks\"\n",
+    ")\n",
     "builder.add_text(\"Machine learning transforms industries\")\n",
     "builder.add_text(\"Neural networks process complex data\")\n",
     "builder.add_text(\"Leann is a great storage saving engine for RAG on your MacBook\")\n",
@@ -238,7 +243,7 @@
     "response = chat.ask(\n",
     "    \"Compare the two retrieved programming languages and tell me their advantages.\",\n",
     "    top_k=2,\n",
-    "    llm_kwargs={\"max_tokens\": 128}\n",
+    "    llm_kwargs={\"max_tokens\": 128},\n",
     ")\n",
     "response"
    ]