apollo_l1_gas_price,apollo_l1_gas_price_config: move exchange_rate_decimals const to config

[sirandreww-starkware]

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[sirandreww-starkware]

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• apollo_consensus_orchestrator: add SNIP-35 integration TODO doc #13982
• apollo_consensus_orchestrator: tmp dirty tests for SNIP-35 (NOT FOR MERGE) #13857
• apollo_l1_gas_price,apollo_l1_gas_price_config: move exchange_rate_decimals const to config #13881 👈 (View in Graphite)
• apollo_consensus_orchestrator: add SNIP-35 proposer-validator symmetry tests #13856
• apollo_consensus_orchestrator: add SNIP-35 module edge case tests #13855
• apollo_consensus_orchestrator: add SNIP-35 e2e test #13821
• apollo_consensus_manager: wire STRK/USD oracle into consensus manager #13820
• apollo_consensus_orchestrator: add SNIP-35 fee_proposal validation #13819
• apollo_consensus_orchestrator: include fee_proposal_fri in proposal commitment hash #13949
• apollo_starknet_client: read fee_proposal_fri from feeder gateway #13986
• apollo_consensus_orchestrator: wire SNIP-35 fee_proposal into cende blob #13985
• apollo_consensus_orchestrator: wire SNIP-35 fee_proposal into build_proposal #13818
• apollo_consensus_orchestrator: add fee_actual floor to EIP-1559 gas price calculation #13824
• apollo_consensus_orchestrator: add SNIP-35 fee_proposals sliding window #13817
• apollo_consensus_orchestrator,apollo_consensus_manager: add strk_exchange_rate_oracle field to deps #13823
• apollo_l1_gas_price_types,apollo_l1_gas_price: rename trait method eth_to_fri_rate to fetch_rate #13987
• apollo_dashboard: add SNIP-35 row #13954
• apollo_consensus_orchestrator: add SNIP-35 metrics #13816
• apollo_consensus_orchestrator: add SNIP-35 module tests #13815
• apollo_consensus_orchestrator: add SNIP-35 module #13854
• apollo_storage: add fee_proposal_fri migrator and bump blocks version to 6.1 #13936 : 2 other dependent PRs (#13814 , #13934 )
• apollo_protobuf: add fee_proposal_fri to sync proto SignedBlockHeader #13957
• starknet_api: add fee_proposal_fri to BlockHeaderWithoutHash #13822
• apollo_protobuf: add fee_proposal_fri to ProposalInit #13812 : 2 other dependent PRs (#13811 , #13935 )
• main

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PR Summary

Medium Risk
Changes L1 gas price oracle validation to depend on a new config field; misconfigured exchange_rate_decimals could cause rate fetch failures and downstream gas price calculation issues.

Overview
Moves the ETH/STRK oracle decimals expectation from a hardcoded constant to a new ExchangeRateOracleConfig.exchange_rate_decimals field (defaulting to 18) and updates ExchangeRateOracleClient to validate responses against this config value.

Updates generated config schema (config_schema.json) accordingly, and simplifies integration tests by dropping the apollo_l1_gas_price crate dependency and hardcoding the mocked oracle response decimals to 18.

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[ShahakShama]

@ShahakShama reviewed 4 files and all commit messages, and made 3 comments.
Reviewable status: all files reviewed, 3 unresolved discussions (waiting on ob1337 and sirandreww-starkware).

---

a discussion (no related file):
I'll make sure with @ob1337 that this is indeed needed

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crates/apollo_integration_tests/src/utils.rs line 573 at r1 (raw file):

    // tests.
    let price = format!("0x{DEFAULT_ETH_TO_FRI_RATE:x}");
    let response = json!({ "timestamp": query.timestamp ,"price": price, "decimals": 18 });

If the decimals are already part of the response, why do we need them as config?

---

crates/apollo_l1_gas_price_config/src/config.rs line 31 at r1 (raw file):

    pub max_cache_size: usize,
    pub query_timeout_sec: u64,
    pub exchange_rate_decimals: u64,

I prefer this won't be a config and will instead be a separate parameter in the ctor. Then, when you initialize eth to strk you'll use 10^18 constant and when you use strk to usd you'll use a different constant