[Epic E6] Scan / observability (dedicated-sync endpoints)

[salindne]

Index the new choice/template and expose funding-side Scan endpoints.

Issues

• [E6-1] Index the new choice + template in Scan #33 [E6-1] Index the new choice + template in Scan
• [E6-2] Dedicated-synchronizer Scan endpoints (funding side only) #34 [E6-2] Dedicated-synchronizer Scan endpoints (funding side only)

Source: docs/planning/extending-mainnet-work-plan.md