cf build selects Vite after migrate --bundler wrangler when Vite is a test dependency

Finding: In an external report, on cf 1.0.0-beta.5 (retested on beta.9) with Wrangler 4.143.0, Vite 8.2.2 and Node 24.18.0 on macOS arm64, running cf migrate with --bundler wrangler succeeds, but a following cf build delegates to vite build and fails with a missing index.html entry when Vite is a declared dev dependency without @cloudflare/vite-plugin (https://github.com/cloudflare/workers-sdk/issues/16108). Reported conditions: a backend-only Worker with a minimal wrangler.jsonc and src/index.ts, "type": "module", and Vite installed (for example for Vitest). Migration reportedly creates cloudflare.config.ts and wrangler.config.ts. cf build then prints a delegation to vite build and fails with the error: "Cannot resolve entry module index.html" (https://github.com/cloudflare/workers-sdk/issues/16108). Control evidence from the reporter: wrangler deploy --dry-run --config wrangler.jsonc passes with the same synthetic source, and removing Vite from declared package dependencies lets cf select Wrangler and build successfully. No deployment or credentials were involved (https://github.com/cloudflare/workers-sdk/issues/16108). A later comment, dated 2026-10-01, says the same credential-free reproduction still fails on cf 1.0.0-beta.9 with the same Wrangler and Vite versions, and that the isolated-package workaround is still needed (https://github.com/cloudflare/workers-sdk/issues/16108#issuecomment-6033601853). Cause: unconfirmed. The reporter's interpretation is that framework autodetection overrides the migration's bundler choice; that is a hypothesis in the report, not a maintainer-confirmed cause. No maintainer response, fix commit or released fix appears in the supplied data, and the issue is open. Possible diagnostic signal, as reported: if cf build output shows delegation to vite build in a project that has Vite only as a test dependency, this matches the reported pattern. Reporter-described workaround: keep a separate package with only cf and Wrangler dev dependencies, leaving the existing Vitest package untouched. Limitation: this is an external report with a synthetic reproduction; it was not reproduced by KFA. Only beta.5 and beta.9 are reported, and the comment coverage may omit middle comments, so behavior on newer versions or real projects is unknown.