feat: single transaction backtesting

[odyslam]

Summary

This PR adds single transaction backtesting and automatic internal call detection to the backtesting framework.

New Features

• Single Transaction Backtesting: Test a specific transaction by passing only its hash via executeBacktestForTransaction()
• Automatic Internal Call Detection: The system automatically detects transactions that call the target contract internally (not just direct calls), with smart fallback:
  1. trace_filter (fastest, requires Erigon/archive node)
  2. debug_traceBlockByNumber (slower but widely supported)
  3. debug_traceTransaction (slowest, per-transaction)
  4. Direct calls only (if no trace APIs available)
• Auto-detect Script Path: No need to manually set CREDIBLE_STD_PATH - the script path is automatically discovered
• Improved Logging: Clear feedback about which detection method is being used and when fallbacks occur

API Changes

Removed: useTraceFilter from BacktestingConfig - trace detection is now automatic with fallback.

// Single transaction backtesting (new)
BacktestingTypes.BacktestingResults memory results = executeBacktestForTransaction(
    0xe5ebeb502ae9ac441fc2912513a7deb9e82bc4d89da91ca41b5fdd51bb96a288,
    targetContract,
    type(MyAssertion).creationCode,
    MyAssertion.check.selector,
    rpcUrl
);

// Block range backtesting (useTraceFilter removed - now automatic)
BacktestingTypes.BacktestingResults memory results = executeBacktest(
    BacktestingTypes.BacktestingConfig({
        targetContract: 0x...,
        endBlock: 1000000,
        blockRange: 100,
        assertionCreationCode: type(MyAssertion).creationCode,
        assertionSelector: MyAssertion.check.selector,
        rpcUrl: "https://...",
        detailedBlocks: false,
        forkByTxHash: true
    })
);

Example Output

=== TRANSACTION DISCOVERY ===
Target: 0xd07822ee341c11a193869034d7e5f583c4a94872
Blocks: 28144849 to 28144849

[INFO] Detecting both direct calls AND internal/nested calls to target
[INFO] Trying trace APIs with automatic fallback...

[TRACE] Using trace_filter API (fastest method for internal call detection)
[TRACE] trace_filter not supported by this RPC endpoint
[TRACE] Falling back to debug_traceBlockByNumber (slower but widely supported)

=== DISCOVERY COMPLETE ===
[INFO] Detection method: debug_traceBlockByNumber
[INFO] Internal calls: ENABLED

Total transactions found: 1

Bug Fixes

• Fix panic error decoding to show human-readable messages
• Fix parsing when zero transactions are found
• Fix whitespace trimming in data extraction
• Fix set -e blocking trace method fallback

Test Plan

• Single transaction backtesting works for direct calls
• Single transaction backtesting works for internal calls
• Block range backtesting finds internal calls via trace APIs
• Automatic fallback chain works when trace methods are unsupported
• Script path auto-detection works

🤖 Generated with Claude Code

[czepluch]

lgtm, did you have time to try it out yet? I can give it a shot a bit later or tomorrow if not