Fix Storybook model cache mocks

[cooper (czxtm)]

Summary

• Adds Storybook Tauri runtime oRPC mocks for model-cache calls used by provider selectors.
• Covers models.setCached, models.getCached, and models.clearCached.
• Split out from Fix critical import finalization bugs #490 for focused review.

Reproduction / verification steps

Regression being verified: provider selectors can call the Storybook model-cache oRPC mock methods used by the app.

cd apps/native
bun run test:unit src/storybook-tauri-runtime.test.ts

Expected result: the test passes and covers models.setCached, models.getCached, and models.clearCached in the Storybook Tauri runtime mock.

Manual Storybook check, if desired:

1. Start Storybook with cd apps/native && bun run storybook.
2. Open a story containing provider/model selectors.
3. Select a CLI/provider model option that causes model-cache calls.
4. Expected: the story remains interactive; no missing models.*Cached oRPC handler error is thrown in the browser console.

Test Plan

• cd apps/native && bun run test:unit src/storybook-tauri-runtime.test.ts

Docs

• No docs update needed

  

[Juanpe Bolívar (arximboldi)]

LGTM 👍