Align Adapter Agent tokens and Linear identity

[realmroot]

What changed

• require client_id=realmroot-cli for delegated Agent tokens
• remove the retired Agent sub-profile dependency
• key Linear external authorization by the stable Linear user
• retain installed Linear workspaces as provider-owned contexts
• update integration documentation and tests

Why

Realmroot now issues one standardized Agent resource-token profile. Linear authorization also needs a stable user identity while allowing multiple workspace contexts.

Validation

• 29 test files and 184 tests
• typecheck and lint
• documentation checks
• production build

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_{🤖 Created by Jarvis via Realmroot}