non-EVM chain labels via full registry import + reference endpoint ladder

- aztec-testnet, solana, ripple x-upstreams now carry their drpc slug as
  chain label (was empty -> dshackle ignored the upstreams)
- reference-rpc-endpoint.json: every chain now has a protocol field
  (eth/bitcoin/solana/ripple/aztec/...) for protocol-family dispatch in
  scripts, plus https://{slug}.drpc.org appended as LAST fallback url
  (independent endpoints stay preferred; overrides win entirely)
- registry grew 247 -> 333 entries (all drpc protocols imported, not just eth)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

solana/agave/solana-testnet-agave-pruned-rocksdb--firesol.yml

@@ -176,7 +176,7 @@ x-upstreams:
           frameSize: 20Mb
           msgSize: 50Mb
           url: $${WS_URL}
-    chain:
+    chain: solana-testnet
     method-groups:
       enabled:
         - debug