fix(ci): set HOME on windows; bump rest shards 6→8 for ubuntu margin

- Windows whole-suite failed deterministically on the lone
  egg_loader.test.ts > getHomedir test: newer windows-latest images leave
  %HOME% unset, so getHomedir() returns os.homedir() (C:\Users\runneradmin)
  while the test asserts it equals process.env.HOME (undefined). Older runner
  images set HOME=USERPROFILE, which is why next was green. Restore that by
  exporting HOME=%USERPROFILE% on windows test jobs — no test change.
- Bump rest shards 6→8 so the two marginal ubuntu shards (rest-1 67s,
  rest-4 61s) drop under 60s with headroom. 24 ubuntu shard groups total.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: killagu

.github/workflows/ci.yml

@@ -103,6 +103,8 @@ jobs:
           - rest-4
           - rest-5
           - rest-6
+          - rest-7
+          - rest-8
         include:
           # macOS/Windows runners have very low concurrency (~5 macOS slots), so
           # fanning out 22 shards × 2 nodes would queue ~9 batches and blow up
@@ -229,6 +231,16 @@ jobs:
         # directly, bypassing the npm `preci` lifecycle, so do it explicitly.
         run: ut run pretest
 
+      - name: Set HOME on Windows
+        # Newer windows-latest runner images leave %HOME% unset, while
+        # @eggjs/core's getHomedir() falls back to os.homedir()
+        # (C:\Users\runneradmin). egg_loader.test.ts asserts
+        # getHomedir() === process.env.HOME, so align HOME with USERPROFILE the
+        # way older runner images did. Unix runners already export HOME.
+        if: ${{ matrix.os == 'windows-latest' }}
+        shell: pwsh
+        run: echo "HOME=$env:USERPROFILE" >> $env:GITHUB_ENV
+
       - name: Run tests (shard ${{ matrix.shard }})
         run: node scripts/run-shard.js ${{ matrix.shard }} -- --coverage
 

scripts/run-shard.js

@@ -70,7 +70,7 @@ const HEAVY_DIRS = new Set(Object.values(HEAVY_SHARDS).map((v) => v.dir));
 // largest-first bin-packing keeps the heaviest leftover dirs (onerror,
 // logrotator, watcher, tegg/plugin/tegg) on separate shards so no single shard
 // dominates. Unlisted dirs default to a small weight.
-const REST_SHARD_COUNT = 6;
+const REST_SHARD_COUNT = 8;
 const REST_DIR_WEIGHTS = {
   'plugins/watcher': 9.7,
   'packages/core': 7.6,