fix(desktop): suppress generic provider warning in onboarding

Hide the red setup notice when the message is the generic missing-provider guidance, since onboarding already presents provider auth actions. Centralize provider-setup matching across desktop hooks and add coverage for the matcher.

apps/desktop/src/lib/provider-setup-errors.test.ts

@@ -0,0 +1,25 @@
+import { describe, expect, it } from 'vitest'
+
+import { isProviderSetupErrorMessage } from './provider-setup-errors'
+
+describe('isProviderSetupErrorMessage', () => {
+  it('matches generic missing-provider copy', () => {
+    expect(isProviderSetupErrorMessage('No inference provider configured. Run `hermes model` to choose one.')).toBe(true)
+    expect(isProviderSetupErrorMessage('No inference provider is configured.')).toBe(true)
+    expect(isProviderSetupErrorMessage('set an API key (OPENROUTER_API_KEY) in ~/.hermes/.env')).toBe(true)
+  })
+
+  it('does not match non-provider runtime failures', () => {
+    expect(
+      isProviderSetupErrorMessage(
+        'Selected runtime is not available. setup.status reports configured credentials.'
+      )
+    ).toBe(false)
+  })
+
+  it('returns false for empty input', () => {
+    expect(isProviderSetupErrorMessage('')).toBe(false)
+    expect(isProviderSetupErrorMessage(null)).toBe(false)
+    expect(isProviderSetupErrorMessage(undefined)).toBe(false)
+  })
+})