[ci] PROBE: salt venv cache key (do not merge)

Chained off #16451. Every job in that PR's CI run cache-hit on the
existing dev caches (Linux-/macOS-/Windows-3.11/3.13/3.14-venv-...),
which means the uv install path the PR introduces was never actually
executed. This branch salts the cache key in the common job so every
downstream restore misses and forces the new ``uv pip install`` lines
to run on every (OS, Python) combo.

Probe only -- close once #16451 is validated.

.github/actions/restore-python/action.yml

@@ -27,6 +27,14 @@ runs:
         path: venv
         # yamllint disable-line rule:line-length
         key: ${{ runner.os }}-${{ steps.python.outputs.python-version }}-venv-${{ inputs.cache-key }}
+    - name: Set up uv
+      # Only needed on cache miss to populate the venv. ``uv pip install``
+      # detects the activated venv via ``VIRTUAL_ENV`` so the venv layout
+      # downstream jobs rely on is preserved.
+      if: steps.cache-venv.outputs.cache-hit != 'true'
+      uses: astral-sh/setup-uv@08807647e7069bb48b6ef5acd8ec9567f424441b # v8.1.0
+      with:
+        enable-cache: true
     - name: Create Python virtual environment
       if: steps.cache-venv.outputs.cache-hit != 'true' && runner.os != 'Windows'
       shell: bash
@@ -34,8 +42,8 @@ runs:
         python -m venv venv
         source venv/bin/activate
         python --version
-        pip install -r requirements.txt -r requirements_test.txt
-        pip install -e .
+        uv pip install -r requirements.txt -r requirements_test.txt
+        uv pip install -e .
     - name: Create Python virtual environment
       if: steps.cache-venv.outputs.cache-hit != 'true' && runner.os == 'Windows'
       shell: bash
@@ -43,5 +51,5 @@ runs:
         python -m venv venv
         source ./venv/Scripts/activate
         python --version
-        pip install -r requirements.txt -r requirements_test.txt
-        pip install -e .
+        uv pip install -r requirements.txt -r requirements_test.txt
+        uv pip install -e .

.github/workflows/ci-api-proto.yml

@@ -26,6 +26,12 @@ jobs:
         uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
         with:
           python-version: "3.11"
+      - name: Set up uv
+        # ``--system`` (below) installs into the setup-python interpreter;
+        # no venv is created or restored by this workflow.
+        uses: astral-sh/setup-uv@08807647e7069bb48b6ef5acd8ec9567f424441b # v8.1.0
+        with:
+          enable-cache: true
 
       - name: Install apt dependencies
         run: |
@@ -34,7 +40,7 @@ jobs:
           sudo apt install -y protobuf-compiler
           protoc --version
       - name: Install python dependencies
-        run: pip install aioesphomeapi -c requirements.txt -r requirements_dev.txt
+        run: uv pip install --system aioesphomeapi -c requirements.txt -r requirements_dev.txt
       - name: Generate files
         run: script/api_protobuf/api_protobuf.py
       - name: Check for changes

.github/workflows/ci.yml

@@ -39,7 +39,11 @@ jobs:
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Generate cache-key
         id: cache-key
-        run: echo key="${{ hashFiles('requirements.txt', 'requirements_dev.txt', 'requirements_test.txt', '.pre-commit-config.yaml') }}" >> $GITHUB_OUTPUT
+        # PROBE: salt prefix forces every venv-cache restore in this
+        # workflow run to miss so the uv install path from #16451 is
+        # actually exercised across Linux/macOS/Windows x 3.11/3.13/3.14.
+        # DO NOT MERGE -- remove this salt before landing.
+        run: echo key="uvprobe-${{ hashFiles('requirements.txt', 'requirements_dev.txt', 'requirements_test.txt', '.pre-commit-config.yaml') }}" >> $GITHUB_OUTPUT
       - name: Set up Python ${{ env.DEFAULT_PYTHON }}
         id: python
         uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
@@ -52,14 +56,22 @@ jobs:
           path: venv
           # yamllint disable-line rule:line-length
           key: ${{ runner.os }}-${{ steps.python.outputs.python-version }}-venv-${{ steps.cache-key.outputs.key }}
+      - name: Set up uv
+        # Only needed on cache miss to populate the venv. ``uv pip install``
+        # detects the activated venv via ``VIRTUAL_ENV`` so downstream jobs
+        # that ``. venv/bin/activate`` see an identical layout.
+        if: steps.cache-venv.outputs.cache-hit != 'true'
+        uses: astral-sh/setup-uv@08807647e7069bb48b6ef5acd8ec9567f424441b # v8.1.0
+        with:
+          enable-cache: true
       - name: Create Python virtual environment
         if: steps.cache-venv.outputs.cache-hit != 'true'
         run: |
           python -m venv venv
           . venv/bin/activate
           python --version
-          pip install -r requirements.txt -r requirements_dev.txt -r requirements_test.txt pre-commit
-          pip install -e .
+          uv pip install -r requirements.txt -r requirements_dev.txt -r requirements_test.txt pre-commit
+          uv pip install -e .
 
   pylint:
     name: Check pylint
@@ -351,14 +363,20 @@ jobs:
         with:
           path: venv
           key: ${{ runner.os }}-${{ steps.python.outputs.python-version }}-venv-${{ needs.common.outputs.cache-key }}
+      - name: Set up uv
+        # Only needed on cache miss to populate the venv.
+        if: steps.cache-venv.outputs.cache-hit != 'true'
+        uses: astral-sh/setup-uv@08807647e7069bb48b6ef5acd8ec9567f424441b # v8.1.0
+        with:
+          enable-cache: true
       - name: Create Python virtual environment
         if: steps.cache-venv.outputs.cache-hit != 'true'
         run: |
           python -m venv venv
           . venv/bin/activate
           python --version
-          pip install -r requirements.txt -r requirements_test.txt
-          pip install -e .
+          uv pip install -r requirements.txt -r requirements_test.txt
+          uv pip install -e .
       - name: Register matcher
         run: echo "::add-matcher::.github/workflows/matchers/pytest.json"
       - name: Run integration tests