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/rust_decimal-49b44c36e17fb9c2/build-script-build-script-build.json

@@ -0,0 +1 @@
+{"rustc":11835527281324007204,"features":"[\"default\", \"serde\", \"std\"]","declared_features":"[\"align16\", \"borsh\", \"bytemuck\", \"c-repr\", \"db-diesel-mysql\", \"db-diesel-postgres\", \"db-diesel2-mysql\", \"db-diesel2-postgres\", \"db-postgres\", \"db-tokio-postgres\", \"default\", \"diesel\", \"legacy-ops\", \"macros\", \"maths\", \"maths-nopanic\", \"ndarray\", \"proptest\", \"rand\", \"rand-0_9\", \"rocket-traits\", \"rust-fuzz\", \"serde\", \"serde-arbitrary-precision\", \"serde-bincode\", \"serde-float\", \"serde-str\", \"serde-with-arbitrary-precision\", \"serde-with-float\", \"serde-with-str\", \"serde_json\", \"std\", \"tokio-pg\", \"tokio-postgres\", \"wasm\", \"zmij\"]","target":5408242616063297496,"profile":11528375766455597691,"path":11954267770261514370,"deps":[],"local":[{"CheckDepInfo":{"dep_info":"debug/.fingerprint/rust_decimal-49b44c36e17fb9c2/dep-build-script-build-script-build","checksum":false}}],"rustflags":[],"config":9396254390672932401,"compile_kind":0}