feat: inspect validation compiler programs and memory

[irvinebroque]

A validation build may load far more TypeScript files than the few containing RPC markers. When memory use grows, we need to see what the compiler actually loaded before deciding what to optimize.

The optional inspect-program command writes the root files, dependencies, and files actually transformed to JSON. It uses the real build transform, so aliases and shadowed imports are handled consistently.

A separate optional report measures memory at three stages and records the environment. It requires --expose-gc. The graph hash identifies the report, not source contents; memory figures vary between runs. The two output paths must differ so one report cannot overwrite the other.

The README and validation guide include commands and interpretation, with a minor changeset. Ordinary builds are unchanged. All 623 Node and Workers tests, build, type checks, and Markdown lint pass.

[github-actions]

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