feat: add sp1Verifier() getter to OPSuccinctFaultDisputeGame

[fakedev9999]

Adds public getter for the SP1_VERIFIER immutable variable to maintain consistency with other immutable getters and improve transparency.

This allows:

• Users/contracts to verify which SP1 verifier is being used
• Off-chain tools to validate proof verification configurations
• Easier debugging and deployment validation

Follows the existing pattern of exposing all immutable constructor parameters (disputeGameFactory, rollupConfigHash, aggregationVkey, etc.).

[github-actions]

Metric	Value
Batch Start	9,562,635
Batch End	9,562,640
Witness Generation (seconds)	0
Execution Duration (seconds)	16
Total Instruction Count	348,167,604
Oracle Verify Cycles	31,420,094
Derivation Cycles	251,438,333
Block Execution Cycles	7,228,658
Blob Verification Cycles	23,288,881
Total SP1 Gas	545,008,682
Number of Blocks	5
Number of Transactions	5
Ethereum Gas Used	236,128
Cycles per Block	69,633,520
Cycles per Transaction	69,633,520
Transactions per Block	1
Gas Used per Block	47,225
Gas Used per Transaction	47,225
BN Pair Cycles	0
BN Add Cycles	0
BN Mul Cycles	0
KZG Eval Cycles	0
EC Recover Cycles	0
P256 Verify Cycles	0