chore: sync main with upstream splice main

Refs ChainSafe/canton-extending-mainnet#114

Summary: Merges the latest upstream canton-network/splice main (f2be6819a, 55 commits since our last sync) into main, keeping the dedicated-synchronizer work intact. Upstream has no Daml changes this time, so no package bump; it brings Canton 3.7 and LATEST_RELEASE 0.9.3. The sync operator follows the SV's move to protocol version 37, and LocalNet's Grafana moves to 13.2.2 for upstream's V2 dashboards.