fix: cache Playwright browsers instead of reinstalling them via apt

performance_smoke burned nearly all of its 15-minute budget before the
benchmark even started, twice in a row: validate.yml had no browser cache
at all, so every browser job paid for a full `playwright install
--with-deps` — apt work the ubuntu-latest image makes redundant, with
unbounded retries against an unreachable azure mirror on top. For a
measuring job that is worse than lost minutes: the timing window competes
with package installation on the same runner.

#175 fixed this for the review pipeline but deliberately left the flag
here, reasoning that a prerelease gate values predictability over
minutes. That reasoning was wrong — the flag is what made the gate
unpredictable.

Browsers are now cached per package-lock hash in smoke, golden,
performance_smoke and the full performance run; installation happens only
on a cache miss and no longer touches apt. performance_smoke keeps
headroom for a cold cache at 20 minutes. If the image ever drops a
required library, Chromium fails to launch with a clear missing-libraries
error; that is the moment to bring the flag back.

Issue: #206
User-Visible: no

.github/workflows/performance.yml

@@ -132,9 +132,17 @@ jobs:
       - name: Install candidate and baseline dependencies
         run: npm ci --prefix candidate && npm ci --prefix baseline
 
+      # То же, что в validate.yml: кэш браузеров, apt не трогаем (#206).
+      - name: Кэш браузеров Playwright
+        id: pw
+        uses: actions/cache@v6
+        with:
+          path: ~/.cache/ms-playwright
+          key: playwright-${{ runner.os }}-${{ hashFiles('candidate/package-lock.json') }}
       - name: Install pinned Chromium
+        if: steps.pw.outputs.cache-hit != 'true'
         working-directory: candidate
-        run: npx playwright install --with-deps chromium
+        run: npx playwright install chromium
 
       - name: Build both exact source trees
         run: |

.github/workflows/validate.yml

@@ -169,8 +169,20 @@ jobs:
           node-version: 22
           cache: npm
       - run: npm ci
-      - name: Install Chromium for Playwright
-        run: npx playwright install --with-deps chromium
+      # Браузеры кэшируются, а apt не запускается вовсе: на GitHub-раннере
+      # системные библиотеки Chromium уже в образе, а --with-deps тратил минуты
+      # и подолгу перебирал недоступное azure-зеркало (#175, #206). Если
+      # библиотека когда-нибудь исчезнет из образа, Chromium не запустится с
+      # внятной ошибкой — тогда флаг вернуть.
+      - name: Кэш браузеров Playwright
+        id: pw
+        uses: actions/cache@v6
+        with:
+          path: ~/.cache/ms-playwright
+          key: playwright-${{ runner.os }}-${{ hashFiles('package-lock.json') }}
+      - name: Install pinned Chromium
+        if: steps.pw.outputs.cache-hit != 'true'
+        run: npx playwright install chromium
       - name: Build a fresh bundle for the smokes
         run: npm run build && cp dist/houseplan-card.js demo/srv/assets/houseplan-card.js
       - name: Smoke suite
@@ -207,8 +219,20 @@ jobs:
           node-version: 22
           cache: npm
       - run: npm ci
+      # Браузеры кэшируются, а apt не запускается вовсе: на GitHub-раннере
+      # системные библиотеки Chromium уже в образе, а --with-deps тратил минуты
+      # и подолгу перебирал недоступное azure-зеркало (#175, #206). Если
+      # библиотека когда-нибудь исчезнет из образа, Chromium не запустится с
+      # внятной ошибкой — тогда флаг вернуть.
+      - name: Кэш браузеров Playwright
+        id: pw
+        uses: actions/cache@v6
+        with:
+          path: ~/.cache/ms-playwright
+          key: playwright-${{ runner.os }}-${{ hashFiles('package-lock.json') }}
       - name: Install pinned Chromium
-        run: npx playwright install --with-deps chromium
+        if: steps.pw.outputs.cache-hit != 'true'
+        run: npx playwright install chromium
       - name: Build the exact source under review
         run: npm run build && cp dist/houseplan-card.js demo/srv/assets/houseplan-card.js
       - name: Capture or verify golden matrix
@@ -233,7 +257,10 @@ jobs:
     # prereleases. The expensive same-runner comparison lives in performance.yml.
     needs: frontend
     runs-on: ubuntu-latest
-    timeout-minutes: 15
+    # 15 минут не хватало, когда установка браузера шла через apt: замер
+    # начинался на исходе окна (#206). Запас на холодный кэш — при попадании
+    # job укладывается в те же минуты, что и раньше.
+    timeout-minutes: 20
     steps:
       - uses: actions/checkout@v7
       - uses: actions/setup-node@v7
@@ -241,8 +268,20 @@ jobs:
           node-version: 22
           cache: npm
       - run: npm ci
+      # Браузеры кэшируются, а apt не запускается вовсе: на GitHub-раннере
+      # системные библиотеки Chromium уже в образе, а --with-deps тратил минуты
+      # и подолгу перебирал недоступное azure-зеркало (#175, #206). Если
+      # библиотека когда-нибудь исчезнет из образа, Chromium не запустится с
+      # внятной ошибкой — тогда флаг вернуть.
+      - name: Кэш браузеров Playwright
+        id: pw
+        uses: actions/cache@v6
+        with:
+          path: ~/.cache/ms-playwright
+          key: playwright-${{ runner.os }}-${{ hashFiles('package-lock.json') }}
       - name: Install pinned Chromium
-        run: npx playwright install --with-deps chromium
+        if: steps.pw.outputs.cache-hit != 'true'
+        run: npx playwright install chromium
       - name: Build the exact candidate source
         run: npm run build && cp dist/houseplan-card.js demo/srv/assets/houseplan-card.js
       - name: Capture the heaviest Glow state