feat!: hooks for fee-on-transfer token support

[kayibal]

Adds the hooks that code built on fynd needs to quote fee-on-transfer tokens: override quote amounts, read the simulation's event logs, simulate on the quote's own block, and follow the market read-only. With these hooks, a caller can learn each token's tax from simulations and correct the quotes.

Quotes

• OrderQuote::set_amount_in and set_amount_out are public.
  • set_amount_out moves amount_out_net_gas by the same difference. A net output already at zero stays at zero.
  • set_amount_in drops the transaction, the fee breakdown and the simulation result, because they were built for the old amount.
• OrderQuote::retract(status) withdraws a solved quote. It keeps only the status and the input amount.
• EncodingOptions::with_slippage replaces the slippage and keeps the other options.

Simulation

• SimulationResult::Success carries logs: Vec<EventLog>, every event the call emitted, undecoded. The field is #[serde(skip)], so the API response does not change.
• New variants:
  • SimulationResult::Reverted for a call that ran and reverted. Failure now means only that the simulation did not run.
  • SimulationResult::BlockUnavailable for a node that does not have the quote's block.
  • Both reach the wire as failure.
• SimulationResult is #[non_exhaustive], like QuoteStatus.
• A quote is simulated on the block it was priced on (quote.block().number()), not on the latest block. The revert trace uses the same block.
• When the node answers "header not found" (or "block not found" / "unknown block"), the simulation is asked again after 500 ms, and after twice the previous wait each time. The retries stop when the waits add up to two block times. All attempts together stay within the simulation request timeout (3 s by default).
• The simulation metrics (quote_simulations_total, quote_simulation_deviation_bps, the gas histograms) carry a purpose label: quote or fee_token_sample.
  • simulate_quotes records quote. The new simulate_quotes_for takes a SimulationPurpose.
  • The two Grafana simulation panels filter on purpose="quote".
• Token layout discovery, for the balance overrides of a simulated sender:
  • It takes an out-of-gas probe as a miss.
  • It finds the balance slot of a reflection token, whose stored balance is scaled by a rate (BalanceEncoding::Scaled).

Market access (behind experimental)

• AppState::market_reader() returns MarketReader, which can read the market data but not write it.
• AppState::subscribe_market_events() returns a receiver of the feed's MarketEvents. SolverParts::market_events() gives the subscribe-only MarketEvents handle it comes from.

Breaking changes

• SimulationResult has new variants, a new field, and is now #[non_exhaustive]. Downstream matches need a fallback arm.
• set_amount_in and set_amount_out change more than the one amount (see above).

Testing

• Unit tests for each change.
  • Mocked RPC tests for block pinning and the retry timing, using wiremock, which is now a dev-dependency of fynd-core.
  • Layout discovery tests for accounts without code, out of gas, and scaled balances.
  • Metrics label tests.
• The whole workspace passes clippy with -D warnings. The three panic-abort tests (test_simulate_path_contains_simulation_panic, test_water_fill_contains_simulation_panic, test_get_amount_out_guarded_converts_panic_to_error) abort locally on macOS, on main too; CI runs them.
• Run against live Ethereum, Base and Robinhood nodes. Quotes and simulations of about 100 fee tokens, including reflection tokens.

🤖 Generated with Claude Code

https://claude.ai/code/session_01KDriANMezML2o1C6T9vP2o

[github-actions]

Breaking API Changes (Intentional)

Breaking API changes detected and declared in the PR title.
release-plz derives the bump from commits: verify a !-marked commit is in this PR so the release PR shows a minor bump (breaking changes on 0.x.x bump the minor).

semver-checks output

Checking fynd-bench-harness v0.112.2 -> v0.112.2 (no change; assume minor)
     Checked [   0.072s] 196 checks: 196 pass, 58 skip
     Summary no semver update required
    Finished [   0.141s] fynd-bench-harness
    Checking fynd-core v0.112.2 -> v0.112.2 (no change; assume minor)
     Checked [   1.232s] 196 checks: 193 pass, 3 fail, 0 warn, 58 skip

--- failure enum_marked_non_exhaustive: enum marked #[non_exhaustive] ---

Description:
A public enum has been marked #[non_exhaustive]. Pattern-matching on it outside of its crate must now include a wildcard pattern like `_`, or it will fail to compile.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#attr-adding-non-exhaustive
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.50.0/src/lints/enum_marked_non_exhaustive.ron

Failed in:
  enum SimulationResult in fynd-core/src/types/quote.rs:1505
  enum SimulationResult in fynd-core/src/types/quote.rs:1505
  enum SimulationResult in fynd-core/src/types/quote.rs:1505

--- failure enum_no_repr_variant_discriminant_changed: enum variant had its discriminant change value ---

Description:
The enum's variant had its discriminant value change. This breaks downstream code that used its value via a numeric cast like `as isize`.
        ref: https://doc.rust-lang.org/reference/items/enumerations.html#assigning-discriminant-values
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.50.0/src/lints/enum_no_repr_variant_discriminant_changed.ron

Failed in:
  variant SimulationResult::Failure 1 -> 2 in fynd-core/src/types/quote.rs:1523
  variant SimulationResult::Failure 1 -> 2 in fynd-core/src/types/quote.rs:1523
  variant SimulationResult::Failure 1 -> 2 in fynd-core/src/types/quote.rs:1523

--- failure enum_struct_variant_field_added: pub enum struct variant field added ---

Description:
An enum's exhaustive struct variant has a new field, which has to be included when constructing or matching on this variant.
        ref: https://doc.rust-lang.org/reference/attributes/type_system.html#the-non_exhaustive-attribute
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.50.0/src/lints/enum_struct_variant_field_added.ron

Failed in:
  field logs of variant SimulationResult::Success in fynd-core/src/types/quote.rs:1515
  field logs of variant SimulationResult::Success in fynd-core/src/types/quote.rs:1515
  field logs of variant SimulationResult::Success in fynd-core/src/types/quote.rs:1515

     Summary semver requires new major version: 3 major and 0 minor checks failed
    Finished [   2.097s] fynd-core
    Checking fynd-test-fixtures v0.112.2 -> v0.112.2 (no change; assume minor)
     Checked [   0.087s] 196 checks: 196 pass, 58 skip
     Summary no semver update required
    Finished [   0.126s] fynd-test-fixtures
    Checking fynd-rpc v0.112.2 -> v0.112.2 (no change; assume minor)
     Checked [   0.118s] 196 checks: 196 pass, 58 skip
     Summary no semver update required
    Finished [   0.186s] fynd-rpc
    Checking fynd-rpc-types v0.112.2 -> v0.112.2 (no change; assume minor)
     Checked [   0.154s] 196 checks: 196 pass, 58 skip
     Summary no semver update required
    Finished [   0.236s] fynd-rpc-types
    Checking fynd-client v0.112.2 -> v0.112.2 (no change; assume minor)
     Checked [   0.174s] 196 checks: 196 pass, 58 skip
     Summary no semver update required
    Finished [   0.281s] fynd-client
    Checking fynd-tools-common v0.112.2 -> v0.112.2 (no change; assume minor)
     Checked [   0.074s] 196 checks: 196 pass, 58 skip
     Summary no semver update required
    Finished [   0.103s] fynd-tools-common