deps: bump ordpool-sdk to ecfdfd3 (mint flow modernized)

Picks up the phase-A SDK work from PLAN-cat21-mint-port.md:
- whitelist surface removed
- createCat21Transaction returns just {txId}
- localStorage allMints$ machinery gone
- new pendingMints$([addresses]) — 30s mempool poll for locktime=21
  txs addressed to the wallet
- new recommendedFees$ — 30s poll of /api/v1/fees/recommended
- new Cat21MintOrchestrator — high-level mint flow service that
  encapsulates the RxJS pipelines the component currently owns

Component refactor (mint surface uses the orchestrator; wallet popover
uses pendingMints$) lands in follow-up commits in phase B.

Author: hans-crypto