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/arbitrage/swap_parser_test.go

@@ -0,0 +1,161 @@
+package arbitrage
+
+import (
+	"testing"
+)
+
+func TestParseSignedInt256(t *testing.T) {
+	sas := &ArbitrageService{}
+
+	tests := []struct {
+		name     string
+		input    []byte
+		expected string
+	}{
+		{
+			name:     "positive value",
+			input:    make([]byte, 32), // All zeros = 0
+			expected: "0",
+		},
+		{
+			name: "negative value",
+			input: func() []byte {
+				// Create a -1 value in two's complement (all 1s)
+				data := make([]byte, 32)
+				for i := range data {
+					data[i] = 0xFF
+				}
+				return data
+			}(),
+			expected: "-1",
+		},
+		{
+			name: "large positive value",
+			input: func() []byte {
+				data := make([]byte, 32)
+				data[31] = 0x01 // Small positive number
+				return data
+			}(),
+			expected: "1",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result, err := sas.parseSignedInt256(tt.input)
+			if err != nil {
+				t.Fatalf("parseSignedInt256() error = %v", err)
+			}
+			if result.String() != tt.expected {
+				t.Errorf("parseSignedInt256() = %v, want %v", result.String(), tt.expected)
+			}
+		})
+	}
+}
+
+func TestParseSignedInt24(t *testing.T) {
+	sas := &ArbitrageService{}
+
+	tests := []struct {
+		name     string
+		input    []byte
+		expected int32
+	}{
+		{
+			name:     "zero value",
+			input:    make([]byte, 32), // All zeros
+			expected: 0,
+		},
+		{
+			name: "positive value",
+			input: func() []byte {
+				data := make([]byte, 32)
+				data[31] = 0x01 // 1
+				return data
+			}(),
+			expected: 1,
+		},
+		{
+			name: "negative value (-1)",
+			input: func() []byte {
+				data := make([]byte, 32)
+				data[28] = 0xFF
+				// Set the 24-bit value to all 1s (which is -1 in two's complement)
+				data[29] = 0xFF
+				data[30] = 0xFF
+				data[31] = 0xFF
+				return data
+			}(),
+			expected: -1,
+		},
+		{
+			name: "max positive int24",
+			input: func() []byte {
+				data := make([]byte, 32)
+				// 0x7FFFFF = 8388607 (max int24)
+				data[29] = 0x7F
+				data[30] = 0xFF
+				data[31] = 0xFF
+				return data
+			}(),
+			expected: 8388607,
+		},
+		{
+			name: "min negative int24",
+			input: func() []byte {
+				data := make([]byte, 32)
+				data[28] = 0xFF
+				// 0x800000 = -8388608 (min int24)
+				data[29] = 0x80
+				data[30] = 0x00
+				data[31] = 0x00
+				return data
+			}(),
+			expected: -8388608,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result, err := sas.parseSignedInt24(tt.input)
+			if err != nil {
+				t.Fatalf("parseSignedInt24() error = %v", err)
+			}
+			if result != tt.expected {
+				t.Errorf("parseSignedInt24() = %v, want %v", result, tt.expected)
+			}
+		})
+	}
+}
+
+func TestParseSignedInt24Errors(t *testing.T) {
+	sas := &ArbitrageService{}
+
+	tests := []struct {
+		name  string
+		input []byte
+	}{
+		{
+			name:  "invalid length",
+			input: make([]byte, 16), // Wrong length
+		},
+		{
+			name: "out of range positive",
+			input: func() []byte {
+				data := make([]byte, 32)
+				// Set a value > 8388607
+				data[28] = 0x01 // This makes it > 24 bits
+				return data
+			}(),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_, err := sas.parseSignedInt24(tt.input)
+			if err == nil {
+				t.Errorf("parseSignedInt24() expected error but got none")
+			}
+		})
+	}
+}