Speed up compile-time stunt generation

[kzu]

Summary

• Static spends its generator time binding each stunt against the user compilation, formatting with NormalizeWhitespace, and rebinding constructors for registration. Metadata bases now bind on a treeless compilation, syntax-only processors skip that compilation update, top-level stunts register from symbols already in hand, and generation plus text emit run in parallel.
• Explicit generic calls such as Select<T> still skip binding when the method name cannot be a generator. That does not change Static, where almost every call is Stunt.Of<T>.

Static benchmark

src/Acceptance/Static/Static.csproj (6,146 generated stunts from about 7,157 Stunt.Of<T>() calls), Release, direct csc /reportanalyzer. DynamicStunts is the same command with Stunts.CompiledProxy.dll removed.

	StuntGenerator	csc wall
Before	81.716 s
After	13.349 s	67.9 s
DynamicStunts (no compile-time stunts)		5.3 s

The generator is about 6x faster. The remaining gap versus DynamicStunts is compiling and analyzing those 6,146 generated types, which dynamic mode does not emit. Set STUNTS_PROFILE to a file path to write a per-phase breakdown; it stays off otherwise.

Test plan

• StuntGeneratorTests (48) and StuntScaffoldTests.EnsureScaffold
• Static csc /reportanalyzer exits 0, numbers above
• Same Static command without the compiled-proxy generator, 5.3 s