🧪 [testing improvement] Add test for word module registration

[Tcode-Motion]

🎯 What: This PR adds a missing test for the module registration logic of the std.word module (stdlib/src/word.rs).

📊 Coverage: The new test_word_module test verifies the initialization state of std.word, specifically confirming its name, version (1.0.0), empty exports, and lack of required capabilities when registered via StdlibRegistry.

✨ Result: Test coverage for stdlib/src/word.rs module registration is established, ensuring that future changes to std.word's registration behavior will be caught if they deviate from expected initialization defaults.

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PR created automatically by Jules for task 7583767144607627607 started by @Tcode-Motion

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