XZBT/docs/evidence/phase1/2026-09-05-runtime-skeleton.md

Phase 1 runtime skeleton — automated evidence

Date: September 5, 2026 Artifact: XZBT.html SHA-256: 8a444a17e06e3d2c4825fcb293004fde4da22c776154fba3d624cc50845c26c3 Result: Implementation and automated verification passed; direct-file restart observation remains pending.

Delivered

• deterministic modular-source build into one inline-script, inline-style HTML artifact;
• multi-file and drag/drop .xzbt loading;
• BOM-aware JSON parsing plus XZBT version, metadata, identifier, root-field, and seed validation;
• exhibit library and inert Phase 1 performance surface;
• prepare-before-teardown activation, complete disposal, and previous-exhibit recovery attempt;
• production SeededRNG using the frozen FNV-1a-32, SplitMix32, and xoshiro128** contract;
• IndexedDB definition cache and last-active-exhibit preference, with a visible session-only fallback;
• bounded structured diagnostics with severity, code, exhibit, section, object, property, and explanation fields;
• two minimal valid exhibits: fixed-seed and cryptographically randomized.

Automated verification

npm run test:phase1 passed 6 of 6 tests. Coverage includes both fixtures, malformed/version/metadata rejection, frozen GC4 PRNG vectors, identical-import no-op and restore, activation failure recovery, byte-identical clean builds, absence of external script/style dependencies, and generated-script compilation.

The existing in-process contract suites also passed unchanged:

• GC2: 12 of 12
• GC3: 8 of 8
• GC4: 7 of 7
• GC5: 8 of 8

git diff --check reported no whitespace errors.

Open acceptance observation

The repository records that prior browser tooling was not permitted to navigate directly to a file: URL, and forbids substituting another browser surface or raw command as a workaround. Consequently, this record does not claim the final Phase 1 direct-file acceptance observation. A supported desktop Chromium user run still needs to import both files from exhibits, switch between them, close the full browser, reopen the same XZBT.html, confirm that both cached exhibits return and the last exhibit activates, and record the Phase 1 GC6 environment fields.