apollo_staking: reorganize contract_types.rs into TryFromIterator and TryFrom<Retdata> sections

[dafnamatsry]

Note

Medium Risk
Moderate risk because it moves Cairo retdata deserialization types (RetdataDeserializationError, CairoArray, CairoOption) into a new shared crate and updates staking to depend on it; mistakes here could break contract-return parsing at runtime, though the logic is largely a direct extraction/refactor.

Overview
Extracts Cairo retdata parsing helpers into a new shared crate. Adds apollo_cairo_utils to the workspace, providing TryFromIterator, CairoArray, CairoOption, and RetdataDeserializationError for deserializing Cairo1 return values (Retdata) into Rust types.

Updates staking to use the shared utilities. apollo_staking now depends on apollo_cairo_utils and removes the duplicated parsing/error definitions from contract_types.rs, switching imports in cairo_staking_contract.rs, staking_contract.rs, and tests accordingly (with no intended behavior change aside from the refactor).

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[reviewable-StarkWare]

This change is 

[dafnamatsry]

• apollo_staking: replace StateReaderFactory with BatcherClient in CairoStakingContract #13319
• apollo_batcher,apollo_batcher_types: add call_contract RPC for executing view entry points #13318
• apollo_staking: reorganize contract_types.rs into TryFromIterator and TryFrom<Retdata> sections #13064 👈 (View in Graphite)
• apollo_staking: implement get_previous_epoch in CairoStakingContract #12902
• main

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[matanl-starkware]

@matanl-starkware reviewed 1 file and all commit messages, and made 1 comment.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on dafnamatsry).

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crates/apollo_staking/src/contract_types.rs line 38 at r1 (raw file):

// Represents a Cairo1 `Option` containing an element that can be deserialized to `T`.
#[derive(Debug)]
pub(crate) struct CairoOption<T>(pub(crate) Option<T>);

Also from prev PR.
These are generic and unrelated to staking.

Code quote:

// Represents a Cairo1 `Array` containing elements that can be deserialized to `T`.
// `T` must implement `TryFrom<[Felt; N]>`, where `N` is the size of `T`'s Cairo equivalent.
#[derive(Debug, PartialEq, Eq)]
struct CairoArray<T>(Vec<T>);

// Represents a Cairo1 `Option` containing an element that can be deserialized to `T`.
#[derive(Debug)]
pub(crate) struct CairoOption<T>(pub(crate) Option<T>);

[github-actions]

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[dafnamatsry]

@dafnamatsry made 1 comment.
Reviewable status: 0 of 9 files reviewed, 1 unresolved discussion (waiting on matanl-starkware).

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crates/apollo_staking/src/contract_types.rs line 38 at r1 (raw file):

Previously, matanl-starkware (Matan Lior) wrote…

Also from prev PR.
These are generic and unrelated to staking.

Done.

[matanl-starkware]

@matanl-starkware reviewed 9 files and all commit messages, and resolved 1 discussion.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on dafnamatsry).

[dafnamatsry]

@dafnamatsry reviewed 9 files and all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on dafnamatsry).

[graphite-app]

Merge activity

• Mar 30, 8:12 AM UTC: Graphite rebased this pull request, because this pull request is set to merge when ready.

[dafnamatsry]

@dafnamatsry reviewed 1 file and all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on dafnamatsry).