[Feature] Design On-Chain Time-Locked Artifact Staking & Energy Recharge Smart Contract Module

[Darkvader-ship-it]

Estimated Effort: 3 weeks / 9 days

Impacted Subsystems / Files:

• contracts/phase-protocol/src/lib.rs
• components/fusion-chamber.tsx
• lib/phase-protocol.ts

Context & Problem Statement:
Utility NFTs currently store energy_level_bp in PhaseState inside contracts/phase-protocol/src/lib.rs, but energy decays statically without an on-chain mechanism to stake artifacts in the Chamber to boost their energy level or earn yield.

Technical Requirements & Scope:

1. Implement stake_artifact(token_id, lock_duration_ledgers) and unstake_artifact(token_id) methods in Soroban contract.
2. Calculate energy level recharge dynamically based on locked duration.
3. Prevent transfers of staked artifacts while locked.
4. Update FusionChamber component in components/fusion-chamber.tsx with staking UI visualizers.

Multi-File Change Surface:
Modifies Rust contract contracts/phase-protocol/src/lib.rs, adds client transaction builders, and updates Chamber state management in components/fusion-chamber.tsx.

Acceptance Criteria:

• Staked NFTs are non-transferable until unlock ledger height.
• Artifact energy level increases linearly with lock duration up to 10,000 BP.

Suggested Approach / Investigation Steps:

1. Add StakedArtifact storage struct and implementation methods in Rust.
2. Write contract unit tests covering unauthorized early unstake attempts.
3. Build UI controls in Chamber terminal for setting lock duration.

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