feat(checker): examples() and spec_files() carry the specification's files

A consumer of the checker crate needs no path into this repository.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HS8WZziDnyxunC23MUxrLp

target/debug/.fingerprint/itoa-0abd08f900c8f906/invoked.timestamp

@@ -0,0 +1 @@
+This file has an mtime of when this was started.

target/debug/.fingerprint/itoa-0abd08f900c8f906/lib-itoa

@@ -0,0 +1 @@
+8f268e5f4e1cb0f2

target/debug/.fingerprint/itoa-0abd08f900c8f906/lib-itoa.json

@@ -0,0 +1 @@
+{"rustc":11835527281324007204,"features":"[]","declared_features":"[\"no-panic\"]","target":18426369533666673425,"profile":2579911162000070427,"path":5686763395482463946,"deps":[],"local":[{"CheckDepInfo":{"dep_info":"debug/.fingerprint/itoa-0abd08f900c8f906/dep-lib-itoa","checksum":false}}],"rustflags":[],"config":9396254390672932401,"compile_kind":0}