Merge branch 'platformio-pch-libretiny' into pch-strict-ci

# Conflicts:
#	esphome/build_gen/arduino8266.py

.github/workflows/ci.yml

@@ -193,9 +193,10 @@ jobs:
     needs:
       - common
     # PR-branch cache saves are invisible to other PRs, so dev pushes seed
-    # the shared entry test-esp8266-native restores. Only dev: the composite
-    # action saves nowhere else, so a beta/release push would download the
-    # toolchain and discard it.
+    # the shared entry the component matrix, the memory impact jobs and
+    # test-esp8266-native restore. Only dev: the composite action saves
+    # nowhere else, so a beta/release push would download the toolchain and
+    # discard it.
     if: github.event_name == 'push' && github.ref == 'refs/heads/dev'
     timeout-minutes: 15
     steps:
@@ -399,14 +400,9 @@ jobs:
       matrix:
         bucket: ${{ fromJson(needs.determine-jobs.outputs.integration-test-buckets) }}
     env:
-      # What the cache steps persist; libdeps is excluded (keyed per xdist
-      # worker and env, it never crosses runs).
-      INTEGRATION_PIO_CACHE_PATH: |
-        ~/.esphome-integration-tests/platformio/platforms
-        ~/.esphome-integration-tests/platformio/packages
-        ~/.esphome-integration-tests/platformio/appstate.json
-        ~/.esphome-integration-tests/platformio/.cache
-        ~/.esphome-integration-tests/platformio/.esphome.pio.stamp.json
+      # Registry libraries (noise-c, libsodium, ArduinoJson, lvgl) the host builds
+      # download, shared per xdist worker by tests/integration/conftest.py
+      INTEGRATION_LIBRARY_CACHE_PATH: ~/.esphome-integration-tests/pio_components
     steps:
       - name: Check out code from GitHub
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
@@ -426,14 +422,13 @@ jobs:
         uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
           python-version: "3.13"
-      - name: Restore integration PlatformIO cache
-        # Native platform + toolchain installed by shared_platformio_cache in
-        # tests/integration/conftest.py; a miss self-heals, so no restore-keys.
-        id: pio-cache
+      - name: Restore integration library cache
+        # A miss or a changed pin self-heals with a download, so no restore-keys
+        id: library-cache
         uses: actions/cache/restore@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
-          path: ${{ env.INTEGRATION_PIO_CACHE_PATH }}
-          key: integration-pio-v1-${{ runner.os }}-py${{ steps.python.outputs.python-version }}-${{ hashFiles('requirements.txt', 'tests/integration/fixtures/cache_init.yaml', 'esphome/components/host/__init__.py') }}
+          path: ${{ env.INTEGRATION_LIBRARY_CACHE_PATH }}
+          key: integration-libraries-v1-${{ runner.os }}-${{ hashFiles('esphome/components/json/__init__.py', 'esphome/components/noise/__init__.py', 'esphome/components/lvgl/__init__.py', 'esphome/components/improv_base/__init__.py') }}
       - name: Restore Python virtual environment
         id: cache-venv
         uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
@@ -501,16 +496,16 @@ jobs:
           # A full cron period of margin for the weekly refresh
           retention-days: 14
       - name: Print ccache statistics
-        # esphome stores the PlatformIO ccache under the machine-global cache
-        # dir (see _ccache_env() in esphome/platformio/toolchain.py).
-        run: CCACHE_DIR="$HOME/.cache/esphome/platformio-ccache" ccache -s
-      - name: Save integration PlatformIO cache
+        # esphome stores the host build's ccache under the machine-global
+        # cache dir (see get_build_env() in esphome/host/toolchain.py).
+        run: CCACHE_DIR="$HOME/.cache/esphome/host/ccache" ccache -s
+      - name: Save integration library cache
         # Bucket 0 only; the others would race the same immutable key.
-        if: success() && (github.ref == 'refs/heads/dev' || contains(github.event.pull_request.labels.*.name, 'ci-cache-write')) && strategy.job-index == 0 && steps.pio-cache.outputs.cache-hit != 'true'
+        if: success() && (github.ref == 'refs/heads/dev' || contains(github.event.pull_request.labels.*.name, 'ci-cache-write')) && strategy.job-index == 0 && steps.library-cache.outputs.cache-hit != 'true'
         uses: actions/cache/save@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
-          path: ${{ env.INTEGRATION_PIO_CACHE_PATH }}
-          key: ${{ steps.pio-cache.outputs.cache-primary-key }}
+          path: ${{ env.INTEGRATION_LIBRARY_CACHE_PATH }}
+          key: ${{ steps.library-cache.outputs.cache-primary-key }}
 
   import-time:
     name: Check import esphome.__main__ time
@@ -1127,6 +1122,11 @@ jobs:
         uses: ./.github/actions/cache-sdk-nrf
         with:
           restore-only: true
+      - name: Cache the native ESP8266 toolchain
+        # Only batches whose test platforms include esp8266; never saves
+        # here, it reuses the install the dev seed job cached.
+        if: matrix.batch.needs_arduino8266
+        uses: ./.github/actions/cache-arduino8266
       - name: Validate and compile components with intelligent grouping
         run: |
           . venv/bin/activate
@@ -1481,12 +1481,9 @@ jobs:
           python-version: ${{ env.DEFAULT_PYTHON }}
           cache-key: ${{ needs.common.outputs.cache-key }}
 
-      - name: Cache platformio
-        if: steps.check-script.outputs.skip != 'true' && steps.check-tests.outputs.skip != 'true' && steps.cache-memory-analysis.outputs.cache-hit != 'true'
-        uses: actions/cache/restore@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
-        with:
-          path: ~/.platformio
-          key: platformio-memory-${{ fromJSON(needs.determine-jobs.outputs.memory_impact).platform }}-${{ hashFiles('platformio.ini') }}
+      - name: Cache the native ESP8266 toolchain
+        if: steps.check-script.outputs.skip != 'true' && steps.check-tests.outputs.skip != 'true' && steps.cache-memory-analysis.outputs.cache-hit != 'true' && fromJSON(needs.determine-jobs.outputs.memory_impact).needs_arduino8266
+        uses: ./.github/actions/cache-arduino8266
 
       - name: Build, compile, and analyze memory
         if: steps.check-script.outputs.skip != 'true' && steps.check-tests.outputs.skip != 'true' && steps.cache-memory-analysis.outputs.cache-hit != 'true'
@@ -1571,11 +1568,9 @@ jobs:
         with:
           python-version: ${{ env.DEFAULT_PYTHON }}
           cache-key: ${{ needs.common.outputs.cache-key }}
-      - name: Cache platformio
-        uses: actions/cache/restore@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
-        with:
-          path: ~/.platformio
-          key: platformio-memory-${{ fromJSON(needs.determine-jobs.outputs.memory_impact).platform }}-${{ hashFiles('platformio.ini') }}
+      - name: Cache the native ESP8266 toolchain
+        if: fromJSON(needs.determine-jobs.outputs.memory_impact).needs_arduino8266
+        uses: ./.github/actions/cache-arduino8266
       - name: Build, compile, and analyze memory
         id: extract
         run: |