_model: devlog-entry
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schema_version: 1
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title: Step 5 Completion: MVP Verification and Reference Exhibits
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date: 2026-09-14
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author: cgcha
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summary: Finalized the Step 5 MVP with 27 automated tests passing, SciFi-XZBT text argument corrections, and browser verification across reference exhibits.
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tags: step5, mvp, verification, reference-exhibits
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source_commit: 961919e017b196104c0c8b6fe4b6881399831186
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body: |
  This devlog entry records the completion of the XZBT-NGN Step 5 MVP.

  The implementation establishes a single-exhibit host engine for XZBT Exhibit Contract 5.2/5.3 capable of negotiating sessions, discovering descriptor-driven controls, dispatching set and invoke operations, and displaying incoming capabilities, events, revisions, and protocol errors.

  Key achievements:
  - **Automated Testing:** All 27 automated unit and integration tests pass cleanly.
  - **Reference Exhibit Alignment:** SciFi-XZBT argument descriptors were corrected, enabling both text line and AI announcement invocations to execute through the generic operator UI.
  - **Conformant Behavior:** Haunted House was verified to report conformant values, and Museum Gallery demonstrated compliant contract negotiation.
  - **Documentation:** Step 5 verification and architecture boundaries are recorded in STEP5-MVP-COMPLETION-REPORT.md.