explorer: read the C-chain through the tip-gated RPC service

An indexer persists the height it reads, so a read from a node below the
chain's tip presents as a rewind: the cursor stalls, or resets. luxd-rpc
selects on lux.network/rpc=fresh, set only while a node serves the tip, so
a read is at the tip or it fails. luxd-headless answers from any member.

Co-authored-by: Hanzo Dev <[email protected]>

deploy/lux-mainnet/explorer.yaml

@@ -311,12 +311,17 @@ configMaps:
       # chain.name aliases on the in-cluster luxd; org chains resolve via their
       # own public HTTPS RPC gateways (raw :9630 LBs are firewalled to non-DO
       # sources, so we use ingress/443 hosts the explorer pod can egress to).
+      # An indexer reads a height and remembers it, so it must never be handed one
+      # from a node below the chain's tip: a lower head reads as a rewind and the
+      # cursor either stalls or wipes. luxd-rpc selects on lux.network/rpc=fresh,
+      # which is only set while a node serves the tip, so every read is at the tip
+      # or the read fails -- luxd-headless answers from any member, tip or not.
       chains:
         - slug: cchain
           name: Lux C-Chain
           chain_id: 96369
           type: evm
-          rpc: http://luxd-headless.lux-mainnet.svc.cluster.local:9630/v1/bc/C/rpc
+          rpc: http://luxd-rpc.lux-mainnet.svc.cluster.local:9630/v1/bc/C/rpc
           # What the BROWSER is told to dial, and it is not optional. `rpc` above is
           # the address this PROCESS dials -- a cluster-internal service name that
           # resolves nowhere outside the mesh. Without public_rpc the binary's
@@ -455,7 +460,7 @@ configMaps:
           # as plain text, 199 errors an hour, which is not a placeholder -- it is
           # noise that buries a real indexing failure. Re-enable with a live
           # endpoint the day an spc L1 exists.
-          rpc: http://luxd-headless.lux-mainnet.svc.cluster.local:9630/v1/bc/spc/rpc
+          rpc: http://luxd-rpc.lux-mainnet.svc.cluster.local:9630/v1/bc/spc/rpc
           coin: SPC
           enabled: false
           indexer: { poll_interval: 30s }