Global settings should mirror Project settings (parity), and allow Authentication/provider keys at project scope

[Automata-intelligentsia]

Summary

Feature request: the Global settings surface should mirror the Project settings surface (same sections/fields), so the same controls are available at both scopes. Two specific points:

1. Parity: every setting exposed at project scope should also be available at global scope (and vice versa), with global acting as the inherited default and project as the override. Currently some settings are only exposed at one scope (e.g. buildTimeoutMs / insightExtractionEnabled have no UI at all — see feat(dashboard): expose build timeout & insight extraction settings in the UI #1935/Allow build timeout & insight extraction to be set as global (user-level) defaults #1938).
2. Authentication at project level: settings traditionally considered "global-only" (notably Authentication / provider API keys) should be allowed at the project level. Use case: a user doing contract/dev work may want to bill a client's API keys only for that client's project, while keeping personal keys global for everything else.

Caveat acknowledged

Some settings genuinely operate at a platform/global level only (e.g. anything tied to the host machine or user account rather than a workspace). Those should remain global-only and be clearly marked — they shouldn't be forced into project scope.

Why

• Consistency: users expect the same knobs in both places, with project overriding global.
• Client billing: project-scoped auth keys are important for anyone running client work where dev costs must be billed to the client's account, not the developer's.

Environment

• Fusion version: 0.56.1