fix(hmr,include): settle a failing boot instead of a silent exit 13

Master's transactional loader made the invalid-provider PTY case regress:
the HMR main watcher's initial scan refreshed the include mid-initial-apply,
the concurrent group updates stranded the include fiber, and once serialized
the failing apply's rollback deadlocked on HMR's refresh drain — dsh exited
13 with no diagnostic and the terminal stranded, the exact symptom this
branch fixes. Serialize every include child-tree mutation through one queue
and pass ignoreInitial to the HMR main watcher; the failing boot now settles
through boot()'s labelled rejection with the tree disposed and exit 1. The
PTY case asserts the settled diagnostic; the fail-loud release remains the
guard for rejections boot cannot see.

packages/ui/app-boot/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/ui/app-boot/README.md
-README.md: 942a09fcfd76b2a8d4735598bea0f42f47f98587
-README.zh.md: 662e43bf441db82ef077ee20a42616c190d766b0
+README.md: 7e0466c40583e6f5b22e0d5ef25d211d595c3216
+README.zh.md: abb796aaa9fd6f8e6ee0578423382ed7f23909ab