fix(web): dev:stub command fails because dev/stub-daemon.mjs is missing

Bug description

The dev:stub script in apps/kimi-web/package.json points to dev/stub-daemon.mjs, but that file does not exist on the main branch. Running the command fails with MODULE_NOT_FOUND.

Reproduction steps

1. Clone the repo and checkout main
2. Run:

   pnpm -C apps/kimi-web run dev:stub
   

3. Observe the error:

   Error: Cannot find module '/.../kimi-code/apps/kimi-web/dev/stub-daemon.mjs'
   code: 'MODULE_NOT_FOUND'
   

Expected behavior

The dev:stub command should start a local stub daemon for offline development, as documented in apps/kimi-web/README.md.

Actual behavior

The command crashes immediately because apps/kimi-web/dev/ directory and stub-daemon.mjs are missing.

Environment

• Branch: main
• Node.js: 24.15.0
• pnpm: 10.33.0

Additional context

• The file is not tracked in origin/main (git ls-tree -r --name-only origin/main | grep stub-daemon returns nothing).
• The directory apps/kimi-web/dev/ does not exist.
• The file is not ignored by .gitignore.
• The file does exist in repository history on other branches (git log --all -- apps/kimi-web/dev/stub-daemon.mjs shows commits), but it never made it to main or was removed at some point.
• README.md still documents this command in the "Offline / no server" section.

I’m happy to help restore or rewrite the stub daemon if the team confirms the intended behavior.

Inspect the dev:stub script in apps/kimi-web/package.json and the Offline / no server section of apps/kimi-web/README.md, then review repository history for apps/kimi-web/dev/stub-daemon.mjs. Run pnpm -C apps/kimi-web run dev:stub to confirm the current failure; done means the documented command starts the local stub daemon without MODULE_NOT_FOUND.