Transaction confirmation and lifecycle tracking

[tac0turtle]

Summary

Implement transaction lifecycle tracking from broadcast through confirmation or rejection.

Parent: #4

Flow

Broadcast (SYNC) → Mempool → Included in Block → Committed
                      │              │
                      ▼              ▼
                   Evicted        Rejected (execution error)

Requirements

Broadcast

• Use BroadcastTxSync (returns after mempool acceptance, not block inclusion)
• Capture tx hash from response
• Handle immediate rejection (invalid tx, mempool full)

Confirmation polling

• Poll TxStatus at configurable interval (default: 1s)
• Timeout after configurable duration (default: 2 minutes)
• Return confirmed height and gas used on success

Eviction handling

• If tx is evicted from mempool, optionally resubmit with same or bumped gas price
• Max resubmission attempts: configurable (default: 1)
• Log eviction events for debugging

Rejection handling

• If tx is included but execution fails, capture error code, codespace, gas wanted/used
• Reset nonce to enable subsequent transactions (Nonce management for transaction submission #8)
• Return structured error with all context

Timeout handling

• If confirmation times out, return error but do NOT assume tx failed (it may still confirm)
• Track "unconfirmed" transactions for later reconciliation

Interface

type TxResult struct {
    TxHash   string
    Height   int64
    GasUsed  int64
    Code     uint32       // 0 = success
    Error    string       // non-empty if Code != 0
    Duration time.Duration // broadcast to confirmation
}

type TxTracker interface {
    Submit(ctx context.Context, txBytes []byte) (*TxResult, error)
    Pending() []string // tx hashes still awaiting confirmation
}

References

• celestia-app pkg/user/tx_client.go — ConfirmTx(), eviction handling
• CometBFT TxStatus endpoint