fix: use Connection RPC for provider status

[tomcatzh]

Summary

• replace the module-local Typert remote markers with a dedicated DSH Connection RPC channel
• route all six provider actions through that channel
• keep status loading, unavailable, and logged-out states distinct in the settings UI
• add focused host dispatch and client registration tests

Why

The web gateway and a plugin can load separate copies of the Typert protocol module. Because its remote registry is module-local, the gateway may not see endpoints registered by the plugin. The resulting status request fails and the UI can incorrectly render an authenticated account as logged out.

Connection RPC is provided by DSH across the host/client boundary and does not depend on shared module identity.

Validation

• npm run check (4 tests)
• npm pack --dry-run
• live status and login-status calls on DSH 0.1.0-rc.7