build: compile-time router optimization

[lukeed]

Already have a PoC for this done – using Babel, but can be anything.

The idea is to remove the Router and regexparam code entirely from the output, even though the Router itself is < 900 bytes and regexparam is less than 400b.

This was a driving feature for #82 – which unfortunately couldn't be part of the initial #94 work. Tried to make worktop.build entirely with swc/core, but not feasible at this time.

Requires AST traversal and modifications. Hoping for evanw/esbuild#1297 (comment) but may end up having to write my own TS parser or bringing in Babel 😖 Major overkill for data/tooling that's already there.