Implement XDP firewall with real-time TUI monitoring

Features:
- High-performance packet filtering via eBPF/XDP
- Instant blocklist with dynamic CLI management
- Exact-match rules with Drop/Pass/Log actions
- CIDR-based IP range dropping via LPM trie
- Token-bucket rate limiting (IP-based and flow-based)
- Auto temp bans for rate limit violators
- Real-time event logging via BPF ring buffer
- Interactive TUI monitor with live stats

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Cargo.toml

@@ -0,0 +1,7 @@
+[workspace]
+resolver = "2"
+members = ["xdp-firewall", "xdp-firewall-common", "xtask"]
+exclude = ["xdp-firewall-ebpf"]
+
+[profile.release]
+lto = true