Fix gatekeeper app navigation after OAuth

[ShibinCo]

What

Refresh the cached gatekeeper app list when the connected-account subscription adds an account that provides a management UI.

OAuth connections arrive through this subscription after the connect popup opens. Without the refresh, the account appears under Gatekeepers but its app remains absent from navigation until a full page reload. The ambient provisioning path already performs the same cache invalidation explicitly.

Verification

• pnpm --filter @gadgets/workshop-frontend types:check
• pnpm --filter @gadgets/workshop-frontend test (24 files, 115 tests)
• pnpm lint:check

[github-actions]

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[kentonv]

Hi @ShibinCo,

Apologies but, per our contributing guide, we prefer not to receive external pull requests. We prefer instead to receive issue reports, which we can then direct our own agents to solve. Could you please file an issue instead?

(I realize that the guide says that trivial PRs are allowed. However, I honestly couldn't tell at a glance what this is doing, and I also noticed you did not accept the CLA. So, I think it's best to proceed with an issue report.)