GCS integration: run down signed urls - #615

these 9 derivations will be built:
  /nix/store/sddd7g87g0slyc22r3rzrmpjhrl6fc6v-psyche-deserialize-zerocopy-wasm-0.2.0.drv
  /nix/store/53fkwfgwqlj6f8sk5lv74153aqlr5sz3-psyche-website-wasm.drv
  /nix/store/miw6z9lzda8yfik97mswaksgyg7hs6hd-solana-coordinator-idl-0.drv
  /nix/store/xjxdgk4xgj35kdfk19mrzpzc7pdiyh51-solana-mining-pool-idl-0.drv
  /nix/store/dp1jd7njm1qajbymq8pl9zvwiqv93f5z-website-shared-1.0.0.drv
  /nix/store/02l0dds72vs8ny435v4x1rxb3zilbv7g-website-frontend-1.0.0.drv
  /nix/store/2wf5hj55lk5fq16g8ic63q9hxs0xf85g-Caddyfile.drv
  /nix/store/c4jznpnan6rydw4nbq6m1ir341670xyd-Caddyfile-formatted.drv
  /nix/store/q20grnv88qr3sa4av5zxjpjjsnk7k5yx-validate-psyche-http-mainnet-caddyfile.drv
these 3 paths will be fetched (1168.54 MiB download, 1196.36 MiB unpacked):
  /nix/store/sqkbmclf2vrmk1fsp31s0y4qxj5c68qw-psyche-deserialize-zerocopy-wasm-deps-0.2.0
  /nix/store/ckzn87jl0bclw7xbw1z6hkkxg408cnnn-solana-idl-solana-coordinator-deps-0.2.0
  /nix/store/pl39ixx9j3c0g52ny0khydhx62gvv9jh-solana-idl-solana-mining-pool-deps-0.2.0
validate-psyche-http-mainnet-caddyfile> 2026/03/17 18:35:57.947	INFO	using config from file	{"file": "./Caddyfile"}
validate-psyche-http-mainnet-caddyfile> 2026/03/17 18:35:57.954	INFO	adapted config to JSON	{"adapter": "caddyfile"}
validate-psyche-http-mainnet-caddyfile> Valid configuration