Synapse support for simplified DataSet terminations and cleanup for GA

[BigLep]

https://www.notion.so/filecoindev/Data-Set-Terminations-Clean-up-360dc41950c1801ebf0aff017a322e7f#360dc41950c180ab9ee4f7ff8cd96e12

[hugomrdias]

From the document:

Implications for Synapse SDK

• New SP-relayed terminateService flow. Client signs a 712, sends to the SP's HTTP endpoint, SP relays to chain. Direct-submit path stays as the backstop when the SP doesn't cooperate.
• Pre-check immediate-eligibility. Inspect FilecoinPay account state before signing the 712 to tell the user whether termination will be immediate or 30-day scheduled. Saves a failed tx and gives clearer UX.
• Watch the SP-submitted tx. SDK receives the tx hash back from the SP, watches for it landing, then signals success and immediate-vs-scheduled outcome to the user (done now vs winding down for 30 days).
• Typehash rename. DeleteDataSet → TerminateService. Breaks existing session keys carrying the DeleteDataSet permission. Needs release notes. fix(typehash)!: rename DeleteDataSet auth to TerminateService #796
• No cleanupPieces API in v1. Permissionless and SP-driven; the SDK doesn't need to expose it to clients.
• createDataSet client-side unchanged. Bond is SP-side msg.value; no client API change.

Docs get cleaner overall: separating terminate from delete (and surfacing the immediate-vs-scheduled distinction) better matches user expectations than the current single-mode flow.