AD-22 Investigate migration to Vite 8 oxc config over esbuild compat

[Finfinder]

Objective

Investigate and plan the migration from the deprecated esbuild config field to the native Vite 8 oxc configuration in electron.vite.config.ts.

Context

Vite 8 introduces a native oxc configuration namespace as the replacement for the esbuild field, which is deprecated. The project currently does not use any esbuild options, so there is no immediate breakage, but future configuration needs (for example define, jsxInject) should use the oxc.* path.

Scope

• Audit the current electron.vite.config.ts for any esbuild field usage.
• Research the Vite 8 oxc configuration API and map any future esbuild options to their oxc equivalents.
• Document the migration path and recommended configuration patterns in docs/vite-config.md or similar.
• If the project adds JS transformation options (define, jsxInject, targets, etc.), implement them under oxc.* rather than esbuild.*.
• Add a deprecation warning or lint rule that flags new esbuild.* usage in the config.

Rationale

The project does not currently use esbuild options, so there is no urgency. However, preparing the migration path now avoids a breaking-change surprise when Vite removes the esbuild compat layer in a future major release.

Benefits

• Proactively prepares the configuration for the removal of the esbuild compat layer.
• Reduces the risk of a breaking change on the next Vite major update.
• Provides clear guidance for contributors adding transformation options in the future.

Definition of Done

• Audit confirms no esbuild field usage in electron.vite.config.ts.
• Migration path and oxc equivalents documented.
• Any new transformation options use oxc.* instead of esbuild.*.
• Lint rule or deprecation warning flags new esbuild.* usage.

Milestone

1.0 Stabilize MVP