1. Get Tips (filtered for unclaimed and unlocked)
   ↓
   getAggregatedTipsByFid(fid: number)
   • Filters: status = 'pending'
   • Filters: tx_hash = null
   • Filters: claim_nonce = null
   • Filters: claim_started_at = null OR expired
   ↓
2. Lock Tips with Unique Nonce
   ↓
   lockTipsForClaiming(tips: Tip[])
   • Generates UUID for claim_nonce
   • Sets claim_started_at timestamp
   • Sets lock_timeout (15 minutes)
   • Updates all tips atomically
   ↓
3. Verify Lock Success
   ↓
   verifyTipsLock(tips: Tip[], claimNonce: string)
   • Checks all tips have our claim_nonce
   • Confirms tips are still pending
   • Ensures tx_hash is still null
   ↓
4. Send Transaction
   ↓
   sendTransaction(tokenAddress, to, amount, decimals, isNative)
   • Handles both native (ETH) and ERC20 tokens
   • Waits for transaction receipt
   • Returns success/failure with hash
   ↓
5. Update Tips with Transaction Hash
   ↓
   updateTipsStatus(tips, txHash, walletAddress, claimNonce)
   • Updates only if claim_nonce matches (atomic)
   • Sets tx_hash, status = 'success'
   • Records claimed_at timestamp
   • Clears claim_nonce and lock
   ↓
6. Release Lock if Anything Fails
   ↓
   releaseTipsLock(tips, claimNonce)
   • Clears claim_nonce
   • Clears claim_started_at
   • Only affects tips with matching nonce