feat: add f41 PDP deal support to deal tracker

[anjor]

Summary

Adds support for tracking f41 PDP (Proof of Data Possession) deals alongside legacy f05 market deals.

Part of Filecoin Foundation contract milestone 1 — depends on go-synapse PR #2 for full integration.

Changes

Model Updates (model/replication.go)

• Added DealType type with values market (legacy f05) and pdp (f41)
• Added DealType field to Deal struct with default 'market'
• Added PDP-specific fields:
  • ProofSetID - on-chain proof set ID
  • ProofSetLive - whether proof set is actively challenged
  • NextChallengeEpoch - next challenge due epoch

Worker Type (model/basetypes.go)

• Added PDPTracker worker type

Migration (model/migrate.go)

• Added inferDealTypes() to set deal_type='market' for existing deals

Deal Tracker (service/dealtracker/dealtracker.go)

• Updated to set DealType: model.DealTypeMarket when inserting market deals

PDP Tracker Service (service/pdptracker/pdptracker.go)

• New service with PDPClient interface for go-synapse integration
• Tracks proof sets for wallets
• Updates deal status based on on-chain state
• Currently a stub awaiting go-synapse merge

CLI Updates

• Added singularity run pdp-tracker command
• Added --deal-type filter to singularity deal list

Next Steps (after go-synapse PR #2 merges)

1. Add go-synapse as a dependency in go.mod
2. Implement PDPClient interface using go-synapse's ProofSetManager
3. Parse piece CIDs from proof set data
4. Add comprehensive tests for PDP tracking

Testing

• Build passes
• Existing tests pass
• PDP-specific tests (pending go-synapse integration)