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/calldata/testdata/payloads/uniswapv3_decrease_liquidity.json

@@ -0,0 +1,12 @@
+{
+  "block_number": "",
+  "contract_name": "UniswapV3PositionManager",
+  "from": "0xe5e58921dfa6602792e3f5624e91d291c01dc135",
+  "function": "decreaseLiquidity",
+  "function_sig": "0x0c49ccbe",
+  "hash": "0x5992966aa1cc733367aa0a00e2b3098b6d0d6b88835affbc43e02e1101ac4b8b",
+  "input_data": "0x0c49ccbe00000000000000000000000000000000000000000000000000000000004c1f2c00000000000000000000000000000000000000000000000000000001e20e0177000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000068ed105b",
+  "protocol": "UniswapV3",
+  "to": "0xc36442b4a4522e871399cd717abdd847ab11fe88",
+  "value": "0"
+}