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>

tests/calculation-validation/types.go

@@ -0,0 +1,61 @@
+package calculation_validation
+
+import (
+	"math/big"
+	"time"
+)
+
+// OpportunityTestData represents extracted opportunity data from logs
+type OpportunityTestData struct {
+	ID               string
+	Timestamp        time.Time
+	TransactionHash  string
+	NetProfitETH     *big.Float
+	NetProfitUSD     *big.Float
+	EstimatedProfit  *big.Float
+	ProfitMargin     float64
+	IsExecutable     bool
+	RejectReason     string
+	Confidence       float64
+	Path             []string
+	SwapSequence     []SwapCalculation
+	ThresholdCheck   *ThresholdCheck
+}
+
+// SwapCalculation represents a V3 swap calculation from logs
+type SwapCalculation struct {
+	AmountIn  *big.Int
+	AmountOut *big.Int
+	Fee       uint32
+	FinalOut  *big.Int
+}
+
+// ThresholdCheck represents a profit threshold validation
+type ThresholdCheck struct {
+	NetProfit    *big.Float
+	MinThreshold *big.Float
+	Passed       bool
+}
+
+// ValidationResult represents the result of validating a calculation
+type ValidationResult struct {
+	OpportunityID    string
+	ExpectedProfit   *big.Float
+	CalculatedProfit *big.Float
+	Difference       *big.Float
+	PercentError     float64
+	IsValid          bool
+	Errors           []string
+	Warnings         []string
+}
+
+// TestReport represents a summary of validation tests
+type TestReport struct {
+	Timestamp            time.Time
+	TotalOpportunities   int
+	ValidCalculations    int
+	InvalidCalculations  int
+	AveragePercentError  float64
+	MaxError             *big.Float
+	ValidationResults    []*ValidationResult
+}