Implement Boost allocation flow — contract call, UI controls, and multiplier preview

[prodbycorne]

Problem

The Boost button on every farm row is permanently disabled with opacity={0.6} and cursor='not-allowed'. No boost allocation flow exists anywhere in the frontend.

The contract exposes a boost mechanism where users can allocate a percentage of their locked position to a boost tier that multiplies credit accrual. None of this is reachable from the UI.

Expected Behaviour

Clicking Boost on a farm row opens a modal that:

1. Shows the user's current boost allocation percentage and the resulting multiplier
2. Lets them slide or type a new allocation percentage (0–100 %)
3. Displays a real-time preview of the new daily credit accrual rate
4. Requires signing and submitting a configure_boost contract call via Freighter

Acceptance Criteria

• Boost modal at src/components/BoostModal/BoostModal.tsx with percentage slider (Chakra Slider) and credit-rate preview
• Credit-rate preview formula: dailyRate × (1 + (boostAllocation / 100) × (multiplier - 1)) where multiplier is fetched from the pool's BoostConfig
• useBoostConfig(poolId) hook added to useSorobanQuery.ts — calls sorobanService.getBoostConfig(poolId) which is currently a stub returning { multiplier: 2, allocationPercentage: 0, isActive: false }
• sorobanService.configureBoost(poolId, publicKey, allocationPercentage, walletApi) implemented with proper Soroban transaction building, simulation, signing, and submission
• The Boost button in EarningRow is enabled only when boostConfig.isActive is true and the user has an active stake; it shows the user's current allocation percentage as a badge
• On success, userPosition cache is invalidated so the farm row reflects the updated boost allocation immediately

Relevant Files

• src/app/farm/page.tsx — EarningRow Boost button (currently disabled)
• src/lib/soroban.ts — getBoostConfig, configureBoost (stub methods)
• src/hooks/useSorobanQuery.ts — useBoostConfig, useConfigureBoost
• src/types/farm.ts — may need boostAllocation added to FarmPosition

[Sparexonzy95]

Hi, I’d like to work on this issue.

I have recently contributed to the SmartDrop farm and Soroban transaction flow areas, including the deposit/lock-assets flow, transaction polling, Freighter signing/submission handling, network mismatch protection, React Query cache invalidation, Vitest coverage, and E2E stability fixes.

For this issue, I plan to implement the full Boost allocation flow end to end:

• Add a BoostModal with Chakra slider/input controls for 0–100% allocation.
• Show the user’s current boost allocation and multiplier.
• Add a real-time daily credit-rate preview using the required formula.
• Add useBoostConfig(poolId) and useConfigureBoost hooks.
• Implement sorobanService.configureBoost with Soroban transaction building, simulation, Freighter signing, submission, and confirmation handling.
• Enable the Boost button only when boost is active and the user has an active stake.
• Show the current allocation percentage as a badge.
• Invalidate the relevant user position cache after success so the farm row updates immediately.

I will keep the implementation scoped to the listed files, preserve the existing transaction patterns, and verify with tests/build before opening the PR.