Files with no @Solid annotations bypass the pipeline, so cross-file @SolidState reads in pure consumers are never lowered #106

Problem

builder.dart's fast bailout (lines ~136-143 in 3.0.0-dev.3):

final hasSolidAnnotation = source.contains(_solidAnnotationHint);
final hasProviderHint = source.contains(_providerCallHint) || source.contains(_environmentCallHint);
if (!hasSolidAnnotation && !hasProviderHint) {
  await buildStep.writeAsString(outputId, source); // verbatim passthrough
  return;
}

means a pure consumer — a file that holds a @SolidState-bearing class via plain constructor injection but declares no @Solid* annotation and no provider call site of its own — never enters the transform pipeline. The #104/#105 registry seeding fix only helps files that are being processed, so it never runs for these files: their cross-file session reads stay silently un-lowered.

Every golden fixture in the #105 suite accidentally masks this: each consumer class carries its own @SolidState control field (loadCount), which is exactly what defeats the bailout.

Severity — reproduced, worse than a wrong comparison

In a real app (advisor frontend), making the auth repository's session a public @SolidState field and regenerating produced, for an annotation-free router.dart guard:

• dart fix's dead_code/unnecessary_null_comparison passes saw the un-lowered Signal<Session?> as always-non-null and collapsed AuthGuard.onNavigation to an unconditional resolver.next(); return; — a generated authentication bypass, surfaced only as dead_code warnings;
• the inverse login-route guard collapsed to unconditionally redirect every /login visit;
• session!.token in annotation-free repositories became session.token → compile error (getter 'token' isn't defined for 'Signal<Session?>') — the lucky failure mode.

Candidate fix

Before the passthrough, do the cheap syntactic pass that #105 already implements: parse the unit, seed candidate type names from instance fields / constructor params (existing skip-set + local-shadowing + combinator rules), and walk the relative imports' registries. Enter the full pipeline iff the resulting registry is non-empty; keep the verbatim passthrough otherwise, preserving the fast path for genuinely solid-free files. Plus a golden fixture whose consumer has zero own annotations — the shape the current suite lacks.