fix: Rename gpu_time → gpu_ms in TaskMetadata

[fakedev9999]

Motivation

Worker sends TaskMetadata { gpu_time: Option<u64> }, but coordinator expects gpu_ms: u64. This field name mismatch causes tenant_gpu_busy_time to always emit 0. A short-term serde alias was added in sp1-cluster#60 as a workaround.

Solution

Rename gpu_time → gpu_ms in TaskMetadata struct definition and all usages. This unifies the field name at the source instead of relying on serde alias compatibility.

Fixes cloud-ops#61

PR Checklist

• Builds and compiles
• No clippy/fmt errors
• Added Tests (N/A - field rename only)
• Breaking changes (Field renamed, but TaskMetadata is internal to sp1_prover)

[github-actions]

Test	Old	New	Diff
bn_test_bn_test_g1_add_100	986709	986702	-0.0007 %
p256_test_recover_high_hash_high_recid	7890512	6404712	-18.8302 %
rustcrypto_bigint_test_bigint_mul_add_residue	1736498	1736496	-0.0001 %
sha_test_sha2_v0_9_9_expected_digest_lte_100_times	1267228	1260630	-0.5207 %
curve25519_dalek_test_decompressed_expected_value	4423017	4545357	2.7660 %
curve25519_dalek_test_ed25519_verify	13269273	13270187	0.0069 %
secp256k1_program_test_verify_v0_30_0_rand_lte_100	17080234	17066102	-0.0827 %
sha_test_sha2_v0_10_8_expected_digest_lte_100_times	1763958	1765532	0.0892 %
bls12_381_tests_test_inverse_fp_100	1434358	1434358	0.0000 %
k256_test_recover_rand_lte_100	4407008	4422442	0.3502 %
bn_test_bn_test_fq_sqrt_100	833212	833212	0.0000 %
k256_test_schnorr_verify	5681064	5662873	-0.3202 %
p256_test_recover_rand_lte_100	15924814	15905806	-0.1194 %
bls12_381_tests_test_bls_add_100	10573308	10573308	0.0000 %
curve25519_dalek_ng_test_zero_msm	125377	125377	0.0000 %
curve25519_dalek_ng_test_add_then_multiply	4635189	4396727	-5.1446 %
sha_test_sha2_v0_10_6_expected_digest_lte_100_times	1765124	1770009	0.2768 %
sha_test_sha2_v0_10_9_expected_digest_lte_100_times	1766053	1762961	-0.1751 %
keccack_test_expected_digest_lte_100	1718234	1716666	-0.0913 %
secp256k1_program_test_recover_rand_lte_100	5453355	5469114	0.2890 %
bls12_381_tests_test_inverse_fp2_100	2764153	2764153	0.0000 %
bn_test_bn_test_g1_double_100	728995	728995	0.0000 %
curve25519_dalek_ng_test_zero_mul	107780	107780	0.0000 %
k256_test_recover_high_hash_high_recid	2082879	2159509	3.6790 %
p256_test_recover_pubkey_infinity	101640	101640	0.0000 %
bls12_381_tests_test_sqrt_fp_100	898689	1003972	11.7152 %
k256_test_recover_pubkey_infinity	97620	97620	0.0000 %
bls12_381_tests_test_bls_double_100	6402221	6402221	0.0000 %
rustcrypto_bigint_test_bigint_mul_mod_special	1753913	1753913	0.0000 %
bls12_381_tests_test_sqrt_fp2_100	1870060	1761854	-5.7862 %
bn_test_bn_test_fq_inverse_100	834812	834812	0.0000 %
bn_test_bn_test_fr_inverse_100	851812	851812	0.0000 %
secp256k1_program_test_verify_rand_lte_100	17068600	17105051	0.2136 %
curve25519_dalek_ng_test_decompressed_noncanonical	195590	195590	0.0000 %
curve25519_dalek_test_add_then_multiply	2977747	2854846	-4.1273 %
p256_test_verify_rand_lte_100	11856660	11865931	0.0782 %
rust_crypto_rsa_test_pkcs_verify_100	28642519	29276162	2.2122 %
secp256k1_program_test_recover_v0_30_0_rand_lte_100	5452235	5458367	0.1125 %
sha_test_sha3_expected_digest_lte_100_times	1609140	1609048	-0.0057 %
k256_test_verify_rand_lte_100	11849933	11921398	0.6031 %
curve25519_dalek_test_decompressed_noncanonical	7660	7660	0.0000 %
curve25519_dalek_test_zero_mul	71797	71797	0.0000 %
curve25519_dalek_test_zero_msm	83453	83453	0.0000 %