ci: add comprehensive CI/CD pipeline with 100% coverage enforcement

Created complete CI/CD infrastructure for V2 development:

GitHub Actions Pipeline (.github/workflows/v2-ci.yml):
- Pre-flight checks (branch naming, commit messages)
- Build & dependency validation
- Code quality with 40+ linters (golangci-lint)
- Unit tests with MANDATORY 100% coverage enforcement
- Integration tests with timeout management
- Performance benchmarks (parser < 5ms, detection < 10ms, e2e < 50ms)
- Decimal precision validation
- Modularity validation (component independence)
- Final validation summary with PR comments

Code Quality (.golangci.yml):
- 40+ enabled linters for comprehensive checks
- Cyclomatic complexity limits (max 15)
- Magic number detection
- Security scanning (gosec)
- Style checking with MEV/DEX terminology
- Test file exclusions for appropriate linters

Build Automation (Makefile):
- build, test, test-coverage with 100% enforcement
- lint, fmt, vet, security targets
- deps-download, deps-verify, deps-tidy, deps-check
- validate (full CI/CD locally)
- bench (performance benchmarks)
- check-modularity, check-circular
- Color-coded output for better UX

Git Optimization (.gitattributes):
- LF normalization for cross-platform consistency
- Binary file handling
- Diff settings for Go files
- Merge strategies
- Export-ignore for archives

Git Hooks (.git-hooks/):
- pre-commit: format, tests, vet, secret detection, go.mod tidy
- commit-msg: message format validation
- README with installation instructions
- install-git-hooks.sh script for easy setup

Documentation (docs/planning/05_CI_CD_SETUP.md):
- Complete pipeline architecture diagram
- Local development workflow
- GitHub Actions job descriptions
- Performance optimizations (caching, parallel execution)
- Failure handling and debugging
- Branch protection rules
- Deployment process
- Best practices and troubleshooting

Performance Targets:
- Pipeline duration: < 15 minutes
- Test coverage: 100% (enforced, non-negotiable)
- Parser latency: < 5ms
- Arbitrage detection: < 10ms
- End-to-end: < 50ms

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

scripts/install-git-hooks.sh

@@ -0,0 +1,97 @@
+#!/bin/bash
+#
+# Install Git hooks for MEV Bot V2
+#
+
+set -e
+
+# Colors
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+NC='\033[0m' # No Color
+
+echo -e "${GREEN}📦 Installing Git hooks for MEV Bot V2...${NC}"
+echo ""
+
+# Get script directory
+SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+REPO_ROOT="$( cd "$SCRIPT_DIR/.." && pwd )"
+HOOKS_DIR="$REPO_ROOT/.git-hooks"
+GIT_HOOKS_DIR="$REPO_ROOT/.git/hooks"
+
+# Check if we're in a git repository
+if [ ! -d "$REPO_ROOT/.git" ]; then
+    echo -e "${RED}❌ Not a git repository${NC}"
+    echo -e "${RED}   Run this script from within the repository${NC}"
+    exit 1
+fi
+
+# Check if hooks directory exists
+if [ ! -d "$HOOKS_DIR" ]; then
+    echo -e "${RED}❌ Hooks directory not found: $HOOKS_DIR${NC}"
+    exit 1
+fi
+
+# Make hooks executable
+echo -e "${YELLOW}Making hooks executable...${NC}"
+chmod +x "$HOOKS_DIR"/pre-commit
+chmod +x "$HOOKS_DIR"/commit-msg
+echo -e "${GREEN}✅ Hooks made executable${NC}"
+echo ""
+
+# Install pre-commit hook
+echo -e "${YELLOW}Installing pre-commit hook...${NC}"
+if [ -f "$GIT_HOOKS_DIR/pre-commit" ] && [ ! -L "$GIT_HOOKS_DIR/pre-commit" ]; then
+    echo -e "${YELLOW}⚠️  Existing pre-commit hook found (not a symlink)${NC}"
+    echo -e "${YELLOW}   Backing up to pre-commit.backup${NC}"
+    mv "$GIT_HOOKS_DIR/pre-commit" "$GIT_HOOKS_DIR/pre-commit.backup"
+fi
+
+ln -sf "../../.git-hooks/pre-commit" "$GIT_HOOKS_DIR/pre-commit"
+echo -e "${GREEN}✅ pre-commit hook installed${NC}"
+echo ""
+
+# Install commit-msg hook
+echo -e "${YELLOW}Installing commit-msg hook...${NC}"
+if [ -f "$GIT_HOOKS_DIR/commit-msg" ] && [ ! -L "$GIT_HOOKS_DIR/commit-msg" ]; then
+    echo -e "${YELLOW}⚠️  Existing commit-msg hook found (not a symlink)${NC}"
+    echo -e "${YELLOW}   Backing up to commit-msg.backup${NC}"
+    mv "$GIT_HOOKS_DIR/commit-msg" "$GIT_HOOKS_DIR/commit-msg.backup"
+fi
+
+ln -sf "../../.git-hooks/commit-msg" "$GIT_HOOKS_DIR/commit-msg"
+echo -e "${GREEN}✅ commit-msg hook installed${NC}"
+echo ""
+
+# Verify installation
+echo -e "${YELLOW}Verifying installation...${NC}"
+if [ ! -L "$GIT_HOOKS_DIR/pre-commit" ]; then
+    echo -e "${RED}❌ pre-commit hook installation failed${NC}"
+    exit 1
+fi
+
+if [ ! -L "$GIT_HOOKS_DIR/commit-msg" ]; then
+    echo -e "${RED}❌ commit-msg hook installation failed${NC}"
+    exit 1
+fi
+
+echo -e "${GREEN}✅ Installation verified${NC}"
+echo ""
+
+# Summary
+echo -e "${GREEN}╔══════════════════════════════════════╗${NC}"
+echo -e "${GREEN}║   ✅ GIT HOOKS INSTALLED ✅          ║${NC}"
+echo -e "${GREEN}╚══════════════════════════════════════╝${NC}"
+echo ""
+echo -e "${GREEN}Installed hooks:${NC}"
+echo -e "  • pre-commit  - Runs quality checks before commits"
+echo -e "  • commit-msg  - Validates commit message format"
+echo ""
+echo -e "${YELLOW}To test the hooks:${NC}"
+echo -e "  git commit --allow-empty -m \"test(hooks): verify git hooks installation\""
+echo ""
+echo -e "${YELLOW}To bypass hooks (emergency only):${NC}"
+echo -e "  git commit --no-verify"
+echo ""
+echo -e "${GREEN}Happy coding! 🚀${NC}"