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/transport/utils.go

@@ -0,0 +1,48 @@
+package transport
+
+import (
+	"encoding/json"
+	"fmt"
+)
+
+// ExtractMessage extracts a message from a byte buffer with length prefix format
+// Format: "length\nmessage_data"
+func ExtractMessage(buffer []byte) (*Message, []byte, error) {
+	// Look for length prefix (format: "length\nmessage_data")
+	newlineIndex := -1
+	for i, b := range buffer {
+		if b == '\n' {
+			newlineIndex = i
+			break
+		}
+	}
+
+	if newlineIndex == -1 {
+		return nil, buffer, nil // No complete length prefix yet
+	}
+
+	// Parse length
+	lengthStr := string(buffer[:newlineIndex])
+	var messageLength int
+	if _, err := fmt.Sscanf(lengthStr, "%d", &messageLength); err != nil {
+		return nil, nil, fmt.Errorf("invalid length prefix: %s", lengthStr)
+	}
+
+	// Check if we have the complete message
+	messageStart := newlineIndex + 1
+	messageEnd := messageStart + messageLength
+	if len(buffer) < messageEnd {
+		return nil, buffer, nil // Incomplete message
+	}
+
+	// Extract and parse message
+	messageData := buffer[messageStart:messageEnd]
+	var msg Message
+	if err := json.Unmarshal(messageData, &msg); err != nil {
+		return nil, nil, fmt.Errorf("failed to unmarshal message: %w", err)
+	}
+
+	// Return message and remaining buffer
+	remaining := buffer[messageEnd:]
+	return &msg, remaining, nil
+}