[Giveaway] Add read-only view functions for giveaway state

[3m1n3nc3]

Description

contracts/geev-core/src/giveaway.rs exposes no read-only view functions. Every other module offers at least one getter — mutual_aid.rs has get_request (line 53), profile.rs has get_profile / resolve_username / get_reputation, governance.rs has get_flag_count / has_flagged — but a client that wants to read a giveaway must decode raw DataKey::Giveaway(id) / DataKey::ParticipantIndex(id, index) storage entries itself. The only lookup helper that exists, find_winner_index (line 317), is private.

This forces the off-chain indexer and the frontend to duplicate the contract's storage layout, which then silently breaks whenever DataKey or the Giveaway struct changes.

User Story

As an Indexer / Frontend Developer,
I want to read giveaway state through contract view functions,
so that I do not have to reimplement the contract's storage layout off-chain.

Requirements and Context

• Files / refs: contracts/geev-core/src/giveaway.rs, contracts/geev-core/src/test.rs, contracts/README.md
• Add get_giveaway(giveaway_id) -> Option<Giveaway>, mirroring MutualAidContract::get_request
• Add get_winners(giveaway_id) -> Vec<Address> and get_participants(giveaway_id) -> Vec<Address>
• Add has_claimed(giveaway_id, winner) -> bool reading DataKey::Claimed(id, winner)
• All getters must be read-only: no require_auth, no storage writes, and return Option / empty Vec instead of panicking on a missing id

Suggested Implementation

1. Add get_giveaway returning Option<Giveaway> from DataKey::Giveaway
2. Add get_winners reading giveaway.winners, empty Vec when absent
3. Add get_participants walking DataKey::ParticipantIndex 0..participant_count
4. Add has_claimed reading DataKey::Claimed(id, winner)
5. Add tests covering populated, empty, and non-existent giveaway ids

Acceptance Criteria

• Giveaway state is readable without decoding raw storage keys
• Getters never panic for unknown ids and never mutate state
• Tests cover populated, empty, and missing-id cases

Submission Guidelines

• Branch: feat/giveaway-view-functions
• Depends on: None
• PR: feat(giveaway): add read-only view functions

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Gap verified against origin/main at 87de441 on 2026-08-27; line references above are from that commit.

[abdulrahamza]

Hi maintainer, I'll like to get assigned into this and I believe I'll deliver a quality and productive PR within a short period of time.

[Carlys17]

I'd like to work on this. I'll add read-only getters to giveaway.rs — get_giveaway, get_winners, get_participants, and has_claimed — that never panic or mutate state, with tests covering populated, empty, and missing-id cases.

[SaintSammi]

Hi team, I'd like to be assigned this issue.

Adding read-only view functions to contracts/geev-core/src/giveaway.rs: get_giveaway, get_winners, get_participants, and has_claimed, mirroring the getter patterns already used in mutual_aid.rs and profile.rs. I'll make sure each one is truly read-only (no require_auth, no storage writes) and returns Option/empty Vec rather than panicking on unknown ids, plus tests covering populated, empty, and missing-id cases.

I'll work off branch feat/giveaway-view-functions and open the PR as feat(giveaway): add read-only view functions once ready. Let me know if it's free to take.

[grantfox-oss]

🦊 GrantFox — @SaintSammi has been assigned to this issue as part of the Third Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #433)
2. Your PR will be reviewed by the geevapp maintainers

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