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/uniswap/cached_bench_test.go

@@ -0,0 +1,27 @@
+package uniswap
+
+import (
+	"math/big"
+	"testing"
+)
+
+func BenchmarkSqrtPriceX96ToPriceCached(b *testing.B) {
+	// Create a test sqrtPriceX96 value
+	sqrtPriceX96 := new(big.Int)
+	sqrtPriceX96.SetString("79228162514264337593543950336", 10) // 2^96
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_ = SqrtPriceX96ToPriceCached(sqrtPriceX96)
+	}
+}
+
+func BenchmarkPriceToSqrtPriceX96Cached(b *testing.B) {
+	// Create a test price value
+	price := new(big.Float).SetFloat64(1.0)
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_ = PriceToSqrtPriceX96Cached(price)
+	}
+}