esbuild: Come up with a way to properly inject debug IDs when `bundle: false`

[lforst]

Right now we are straight-up stomping on the entrypoints which is gonna break with 100% probability.

The behaviour of bundle: false is basically marking everything except for the resolved entrypoint as external. Since we proxy the entrypoint, everything except our proxy is omitted.

Solution brainstorm:

• Build completely separate logic for when bundle: false
• Use inject option somehow, (maybe one inject per entrypoint and only resolve 1:1)
• Intermediary solution: Emit warning/error when trying to inject with bundle: false
• Intermediary solution: Inject post-build