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/build/serde_json-7839a7dd090f34de/invoked.timestamp

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

target/debug/build/serde_json-7839a7dd090f34de/output

@@ -0,0 +1,3 @@
+cargo:rerun-if-changed=build.rs
+cargo:rustc-check-cfg=cfg(fast_arithmetic, values("32", "64"))
+cargo:rustc-cfg=fast_arithmetic="64"

target/debug/build/serde_json-7839a7dd090f34de/root-output

@@ -0,0 +1 @@
+/tmp/claude-1000/-home-swaits-Code-wanderbooks/dadefedb-8c25-4271-8f56-da5f226f635b/scratchpad/bookspec/target/debug/build/serde_json-7839a7dd090f34de/out