Reject ambiguous registrations before polling

[rmcdaniel]

Change

Reject duplicate workflow and activity wire names in the production Worker before contacting Server. Reject conflicting signal, query, update and validator names at class decoration. DuplicateRegistrationError is a public SDK error with the kind, wire name and both definitions.

Python method resolution stays explicit: overriding the same attribute is valid, while different resolved attributes cannot claim the same name within one handler kind. Worker, Replayer and test-environment admission independently apply the same resolved-handler validation, including programmatically defined classes. Names are scoped to each Worker/Replayer and each handler kind. The workflow test environment rejects replacement by a different class and keeps same-class registration idempotent for automatic execution. Explicit activity mock setters still allow replacement.

Refs #105. Prepares routine SDK 2.5.4 with unchanged wire protocol and supported Server floor. Publication and issue closure follow exact main, registry and ordinary consumer qualification.

Verification

• Initial controls:14 fail against the unchanged baseline,9 existing behavior controls pass. The complete new set passes36 cases after repair, including12 programmatic-class admission controls.
• Worker, registration and official replay corpus suite:312 passed,2 explicit skips. Type checking passes32 source files and lint passes.
• A new official fixture exercises actual Worker admission before replay of a committed activity history. It fails against a fresh PyPI2.5.3 installation and passes against the repair. The installed baseline Worker SHA256 matches exact tag2.5.3.
• Full Python3.10–3.12, regression policy, package, portal and connected integration checks remain required before merge.