fix(ui): restore ChatGPT cards after revisit

[UnlastingR]

ChatGPT can remount a historical DevSpace widget without replaying the original MCP tool-result event. In that path the iframe starts with no card and stays on Waiting for a tool result., which matches the historical-widget behavior reported in #74 and can leave many dead-looking widgets behind in long conversations.

This persists the complete DevSpace card snapshot in ChatGPT widget state, restores it during widget boot, and falls back to ChatGPT's historical toolOutput / toolResponseMetadata globals when no persisted snapshot is available. It also listens for openai:set_globals in case those globals arrive after boot. The widget resource URI is versioned and the ChatGPT openai/outputTemplate alias is advertised so existing template caching does not keep serving the older bootstrap behavior.

The regression coverage checks widget-state round trips, malformed-state rejection, historical-global rehydration, precedence of persisted state, and the tool metadata used by ChatGPT. The portable MCP Apps path remains unchanged when the ChatGPT-specific bridge is unavailable.

Summary by CodeRabbit

• New Features

  • Added persistence for workspace result cards, allowing cards to be restored when reopening or reconnecting to the app.
  • Preserves card content and state across host updates, prioritizing saved state during conflicts.
  • Added compatibility for restoring cards from supported host-provided tool results.
  • Improved compatibility with ChatGPT-hosted workspace widgets.

• Bug Fixes

  • Invalid or incomplete saved card data is safely ignored so the workspace continues rendering normally.
  • Improved validation prevents malformed card content from being displayed.