feat: create v2-prep branch with comprehensive planning

Restructured project for V2 refactor:

**Structure Changes:**
- Moved all V1 code to orig/ folder (preserved with git mv)
- Created docs/planning/ directory
- Added orig/README_V1.md explaining V1 preservation

**Planning Documents:**
- 00_V2_MASTER_PLAN.md: Complete architecture overview
  - Executive summary of critical V1 issues
  - High-level component architecture diagrams
  - 5-phase implementation roadmap
  - Success metrics and risk mitigation

- 07_TASK_BREAKDOWN.md: Atomic task breakdown
  - 99+ hours of detailed tasks
  - Every task < 2 hours (atomic)
  - Clear dependencies and success criteria
  - Organized by implementation phase

**V2 Key Improvements:**
- Per-exchange parsers (factory pattern)
- Multi-layer strict validation
- Multi-index pool cache
- Background validation pipeline
- Comprehensive observability

**Critical Issues Addressed:**
- Zero address tokens (strict validation + cache enrichment)
- Parsing accuracy (protocol-specific parsers)
- No audit trail (background validation channel)
- Inefficient lookups (multi-index cache)
- Stats disconnection (event-driven metrics)

Next Steps:
1. Review planning documents
2. Begin Phase 1: Foundation (P1-001 through P1-010)
3. Implement parsers in Phase 2
4. Build cache system in Phase 3
5. Add validation pipeline in Phase 4
6. Migrate and test in Phase 5

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

orig/pkg/math/mock_gas_estimator.go

@@ -0,0 +1,62 @@
+package math
+
+import (
+	"math/big"
+)
+
+// MockGasEstimator implements GasEstimator for testing purposes
+type MockGasEstimator struct {
+	currentGasPrice *UniversalDecimal
+}
+
+// NewMockGasEstimator creates a new mock gas estimator
+func NewMockGasEstimator() *MockGasEstimator {
+	dc := NewDecimalConverter()
+	gasPrice, _ := dc.FromString("20", 9, "GWEI") // 20 gwei default
+
+	return &MockGasEstimator{
+		currentGasPrice: gasPrice,
+	}
+}
+
+// EstimateSwapGas estimates gas for a swap
+func (mge *MockGasEstimator) EstimateSwapGas(exchange string, poolData *PoolData) (uint64, error) {
+	// Different exchanges have different gas costs
+	switch exchange {
+	case "uniswap_v3":
+		return 150000, nil // 150k gas for Uniswap V3
+	case "uniswap_v2", "sushiswap":
+		return 120000, nil // 120k gas for Uniswap V2/SushiSwap
+	case "camelot":
+		return 130000, nil // 130k gas for Camelot
+	case "balancer":
+		return 200000, nil // 200k gas for Balancer
+	case "curve":
+		return 180000, nil // 180k gas for Curve
+	default:
+		return 150000, nil // Default to 150k gas
+	}
+}
+
+// EstimateFlashSwapGas estimates gas for a flash swap
+func (mge *MockGasEstimator) EstimateFlashSwapGas(route []*PoolData) (uint64, error) {
+	// Flash swap overhead varies by complexity
+	baseGas := uint64(200000) // Base flash swap overhead
+
+	// Add gas for each hop
+	hopGas := uint64(len(route)) * 50000
+
+	return baseGas + hopGas, nil
+}
+
+// GetCurrentGasPrice gets the current gas price
+func (mge *MockGasEstimator) GetCurrentGasPrice() (*UniversalDecimal, error) {
+	return mge.currentGasPrice, nil
+}
+
+// SetCurrentGasPrice sets the current gas price for testing
+func (mge *MockGasEstimator) SetCurrentGasPrice(gasPriceGwei int64) {
+	dc := NewDecimalConverter()
+	gasPrice, _ := dc.FromString(big.NewInt(gasPriceGwei).String(), 9, "GWEI")
+	mge.currentGasPrice = gasPrice
+}