Create standalone browser port of LTX Athena with authenticated native API transport

docs/VALIDATION.md

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+# Validation — initial web preview
+
+2026-09-29:
+
+- `npm run typecheck`: passed.
+- `npm run build`: passed. Vite reports a large inherited editor bundle; splitting
+  the editor into a lazy-loaded chunk is a future performance improvement.
+- `npm test`: 8 tests passed (7 HTTP/media integrations + 1 error-presentation test).
+- Browser smoke test against `scripts/ui-fixture.mjs`, which never contacts Athena:
+  sign-in; new project; reload and reopen saved project; Gen Space renders backend
+  model options; synthetic native API failure shows a recoverable error dialog;
+  timeline editor opens; synthetic 1-second clip upload/import returns dimensions
+  and thumbnail in the asset library.
+- Source LTX-Athena working-tree changes left untouched.
+
+Not verified yet: Docker image build/run on Debian, real LTX generation through
+Athena Deck's selected Video endpoint, remote file permissions/mount paths,
+long-running job recovery/cancellation, all editor interactions and all LTX modes.
+No Athena service was started, stopped or reconfigured during this port.
+
+The synthetic fixture uses a fixed public test password and isolated temporary
+media storage on loopback port 18118. Never deploy that fixture as the real service.
+Production start (`server/index.mjs`) requires an operator-provided password file.