fix(app): autocomplete configured references

[opencode-agent]

Summary

• load configured project references for desktop/app prompt @ autocomplete
• render reference aliases alongside agents/files and insert them as directory file parts
• preserve reference alias filename/mime through prompt DOM parsing and request-part building

Fixes #34106

Tests

• bun typecheck (packages/app)
• bun test src/components/prompt-input/build-request-parts.test.ts (packages/app)
• git push origin fix-web-windows-cwd (pre-push ran bun turbo typecheck)