test: 新增单测 CI 门禁与规范文档，处理 #5868/#5873 review 反馈 (#5877)

.github/workflows/test.yml

@@ -0,0 +1,48 @@
+name: Unit Tests
+
+on:
+  # 指向 v2 的 PR 与推送都跑全量单测，作为合并门禁
+  pull_request:
+    branches:
+      - v2
+  push:
+    branches:
+      - v2
+  # 允许手动触发
+  workflow_dispatch:
+
+jobs:
+  pytest:
+    runs-on: ubuntu-latest
+    name: Unit Tests
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+          cache: 'pip'
+
+      - name: Cache pip dependencies
+        uses: actions/cache@v4
+        with:
+          path: ~/.cache/pip
+          key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.in', '**/requirements.txt') }}
+          restore-keys: |
+            ${{ runner.os }}-pip-
+
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip setuptools wheel
+          # 用 requirements.in 还原 CI / 全新环境（含 pytest~=8.4 与 moviepilot-rust 等可选扩展），
+          # 与本地"干净 venv 复现"一致；测试运行器 pytest 已在 requirements.in 中声明。
+          pip install -r requirements.in
+
+      - name: Run tests
+        run: |
+          # tests/run.py 以 pytest 跑 tests 全量；tests/conftest.py 在收集前把 CONFIG_DIR
+          # 指向临时库并建表，测试杜绝真实网络/外部服务（详见 docs/testing.md）。
+          python tests/run.py