The 148-day WGA strike ends with a tentative agreement whose AI provisions become Hollywood's first enforceable guardrails: AI can't write or rewrite literary material, AI output is not 'source material,' studios must disclose if any material handed to a writer was AI-generated, and writers cannot be required to use AI tools. The contract is ratified weeks later and immediately reframes the AI-and-creativity conversation from speculation to negotiated industry rule. Every studio AI experiment after this is shaped by what writers were and were not willing to live with.