Contributor Tiering & Metadata Badges

[Chrisbankz0]

Closes #427

Summary

Extends the contributor-registry Soroban smart contract to support on-chain badge tiering and metadata. ContributorData now carries a badges: Vec<u32> field (integer IDs to minimise storage costs) and a badge_bitmask: u64 mirror that lets the Vault perform O(1) tier checks without iterating the full vector. A new admin-gated award_badge function writes both fields atomically, while revoke_badge keeps them in sync on removal. get_tier_multiplier exposes the best-tier multiplier in basis points so the Vault can apply reward multipliers in matching pools without any additional storage reads.

Linked Issue

Closes #427

Type of Change

• feat
• fix
• docs
• refactor
• test
• chore

Validation

• Lint passed for affected area(s)
• Tests passed for affected area(s) — 34 unit tests via cargo test --features testutils
• Manual verification completed (if applicable) — deployed to Stellar testnet; award_badge and get_tier_multiplier invoked via Soroban CLI and returned expected values

Documentation

• Documentation updated (or N/A with explanation) — inline rustdoc added to all public types and functions; badge ID → tier → multiplier table documented in lib.rs module header
• Screenshots/videos attached for UI changes — N/A (smart contract only, no UI changes)

Checklist

• Branch name uses feat/, fix/, or docs/ — feat/contributor-badges
• Commit messages follow Conventional Commits — feat: contributor tiering and metadata badges (#427)
• PR scope matches linked issue acceptance criteria

---

Implementation Notes

ContributorData additions

pub badges: Vec<u32>,    // ordered list of awarded badge IDs
pub badge_bitmask: u64, // bitmask mirror — bit N set when badge ID N is held

New public functions

Function	Caller	Description
award_badge(admin, contributor, badge_id)	Admin only	Awards a badge; rejects duplicates and IDs > 63
revoke_badge(admin, contributor, badge_id)	Admin only	Removes a badge and updates bitmask
get_tier_multiplier(contributor)	Vault / anyone	Returns best multiplier in bps (100–200)
has_badge(contributor, badge_id)	Vault / anyone	O(1) bitmask check
get_badge_bitmask(contributor)	Vault / anyone	Raw bitmask for multi-badge checks

Badge tier table

ID	Name	Multiplier
0	Newcomer	100 bps (1×)
1	Contributor	110 bps (1.1×)
2	Trusted	125 bps (1.25×)
3	Veteran	150 bps (1.5×)
4	Core	175 bps (1.75×)
5	Legend	200 bps (2×)
6–63	Reserved	100 bps (1×)

Test coverage — cargo test --features testutils

running 34 tests
test test_initialize_sets_admin                    ... ok
test test_double_initialize_panics                 ... ok
test test_transfer_admin                           ... ok
test test_transfer_admin_non_admin_panics          ... ok
test test_register_contributor_success             ... ok
test test_contributor_count_increments             ... ok
test test_double_register_panics                   ... ok
test test_get_contributor_returns_none_for_unknown ... ok
test test_award_badge_sets_vector_and_bitmask      ... ok
test test_award_multiple_badges                    ... ok
test test_get_badges_helper                        ... ok
test test_has_badge_true_and_false                 ... ok
test test_get_badge_bitmask                        ... ok
test test_award_badge_non_admin_panics             ... ok
test test_award_badge_unknown_contributor_panics   ... ok
test test_award_badge_invalid_id_panics            ... ok
test test_award_duplicate_badge_panics             ... ok
test test_revoke_badge_removes_from_vector_and_bitmask ... ok
test test_revoke_badge_not_held_panics             ... ok
test test_revoke_badge_non_admin_panics            ... ok
test test_update_reputation                        ... ok
test test_update_reputation_non_admin_panics       ... ok
test test_get_tier_multiplier_no_badge_returns_base    ... ok
test test_get_tier_multiplier_unknown_contributor      ... ok
test test_get_tier_multiplier_newcomer             ... ok
test test_get_tier_multiplier_contributor_tier     ... ok
test test_get_tier_multiplier_veteran              ... ok
test test_get_tier_multiplier_legend               ... ok
test test_get_tier_multiplier_best_badge_wins      ... ok
test test_multiplier_after_revoke_drops            ... ok
test test_max_badge_id_is_valid                    ... ok
test test_has_badge_unknown_contributor_returns_false  ... ok
test test_has_badge_out_of_range_returns_false     ... ok
test test_timestamps_update_on_activity            ... ok
test result: ok. 34 passed; 0 failed; 0 ignored

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@Chrisbankz0 Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

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