ci: install the electron binary on every OS for e2e

The macOS e2e leg failed with "Electron failed to install correctly": the
electron postinstall (extract-zip) drops the binary on the macOS runner too, not
just Linux, so guarding the install step to ubuntu left macOS without a binary.
Run install.js on every OS and keep the unzip repair as a Linux-only fallback.

Note: AI-assisted (Claude Code). Manually verified: the workflow yaml parses;
this mirrors the binary-install approach that the Linux leg already relied on,
extended to macOS where the same postinstall gap appears in CI.

Author: notluquis

.github/workflows/e2e.yml

@@ -37,23 +37,25 @@ jobs:
           node-version: '24.x'
           cache: 'yarn'
       - run: yarn install --frozen-lockfile
-      # electron's postinstall (extract-zip) leaves dist without the `electron`
-      # binary on this runner even though the downloaded zip is complete and
-      # valid, so launch fails with "Electron failed to install correctly". Let
-      # install.js fetch the zip into the cache, then extract it with the system
-      # `unzip` and point path.txt at the binary. Linux-only: the zip is the
-      # linux-x64 build and the binary lives at dist/electron. On macOS the
-      # postinstall extracts dist/Electron.app correctly and needs no workaround.
+      # The electron postinstall (extract-zip) intermittently leaves dist without
+      # the binary on CI runners (it happens on macOS too, not just Linux), so
+      # launch fails with "Electron failed to install correctly". Run install.js
+      # explicitly on every OS to fetch and extract the binary.
       - name: Install the Electron binary
+        run: node node_modules/electron/install.js
+      # On Linux, if extract-zip still dropped the binary, fall back to system
+      # unzip (the zip is the linux-x64 build, binary at dist/electron).
+      - name: Repair the Electron binary on Linux if needed
         if: matrix.os == 'ubuntu-latest'
         run: |
           set -euo pipefail
-          node node_modules/electron/install.js || true
-          zip=$(ls ~/.cache/electron/*/electron-*-linux-x64.zip | head -1)
-          rm -rf node_modules/electron/dist
-          mkdir -p node_modules/electron/dist
-          unzip -q -o "$zip" -d node_modules/electron/dist
-          printf 'electron' > node_modules/electron/path.txt
+          if [ ! -x node_modules/electron/dist/electron ]; then
+            zip=$(ls ~/.cache/electron/*/electron-*-linux-x64.zip | head -1)
+            rm -rf node_modules/electron/dist
+            mkdir -p node_modules/electron/dist
+            unzip -q -o "$zip" -d node_modules/electron/dist
+            printf 'electron' > node_modules/electron/path.txt
+          fi
           test -x node_modules/electron/dist/electron
       - run: yarn build
       # Electron needs system libraries; xvfb provides a display on the headless