Static build: frame/panel URLs are still absolute when output is hosted at a subpath

Describe the bug

Follow-up to vitejs/devtools#554.

After the fix, the root redirect and the DevTools SPA itself resolve correctly under a deploy base, but the URLs baked into the emitted manifests and RPC dumps are still root-absolute, so every sub-panel 404s.

Reproduction

Clone https://github.com/arkadiusz-swierczek-pm/vite-devtools-static-output-subpath;
npm ci;
npm run build -- --base /ci-build-123456/;
node server.ts

System Info

System:
    OS: Windows 11 10.0.26200
    CPU: (12) x64 Intel(R) Core(TM) i7-10850H CPU @ 2.70GHz
    Memory: 19.77 GB / 31.61 GB
  Binaries:
    Node: 24.14.0 - C:\Program Files\nodejs\node.EXE
    npm: 11.9.0 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Chrome: 153.0.8010.52
    Edge: Chromium (152.0.4191.53)
    Firefox: 148.0 - C:\Program Files\Mozilla Firefox\firefox.exe

Used Package Manager

npm

Validations

• Follow our Code of Conduct
• Read the Contributing Guide.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Check that this is a concrete bug. For Q&A, please open a GitHub Discussion instead.
• The provided reproduction is a minimal reproducible of the bug.

Run the provided reproduction with npm ci and npm run build -- --base /ci-build-123456/, then inspect the emitted manifests and RPC dumps for the root-absolute frame and panel URLs. Trace where those URLs are generated and verify that the emitted links resolve under the configured subpath without causing panel 404s.