[Dimank92]

Summary

Closes #200

Implements the complete feeder management and governance admin surface for price_oracle:

• Atomic Global Feeder Rotation: rotate_feeder replaces an active feeder with a new feeder in a single atomic transaction, preventing duplicate feeders, self-rotations, and emitting feeder_rotated(old, new).
• Multisig Feeder Rotation: rotate_feeder_via_multisig validates and consumes proposal approvals through the pinned multisig contract.
• Symbol-Specific Feeder Governance:
  • add_feeder_for_symbol: registers dedicated feeders for individual asset symbols (symbol_feeder_added).
  • remove_feeder_for_symbol: removes feeders with strict quorum underrun validation (Error::BelowQuorum if active feeders drop below min_reports, emitting symbol_feeder_removed).
  • rotate_feeder_for_symbol: atomically rotates symbol-specific feeders (symbol_feeder_rotated).
  • Query views: is_feeder_for_symbol, get_feeder_count_for_symbol, get_feeders_for_symbol.
• Effective Feeder Resolution: storage::effective_feeder_list(env, symbol) prioritizes symbol-specific feeders when configured, seamlessly falling back to global feeders for full backwards compatibility.
• Aggregate Recalculation: current_price resolves and averages reports from the effective feeder list.

Test Verification

All 157 unit, property, and admin tests in zenith-price-oracle pass cleanly:

test result: ok. 157 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 6.02s

Clippy passes with 0 warnings:

cargo clippy -p zenith-price-oracle --tests --no-deps -- -D warnings

Payout Address

• Wallet: 0xC345C07229307d4f1c7935aD2cAe48e390215808
• Network: Polygon / Base / Arbitrum / Stellar