feat!: universal redesign — drop Minecraft stack, single-crate architecture

- remove Java plugins (velocity/paper), dashboard, all MC-specific code
  (handshake, death_code, varint, hostname-HMAC); available in history pre-v0.2
- merge crates/* into one package with src/bin/{rampart,rampart-manager,rampart-cli}
- ProtocolHandler trait + registry (no implementations yet), universal PoW kept
- XDP: universal L3/L4 filter (xdp/core/) + pluggable hook API (xdp/hooks/),
  fix IPv6 saddr bug; clang build verified
- docs: bilingual knowledge base (docs/kb/: attacks x4, defense-levels,
  practice x3), rewrite README/architecture for universal concept
- TODO.md v4.0: <=300-line module limit, competitor benchmark section (ref/)
- deploy/CI/docs cleanup: no MC references, new binary names

cargo build/clippy(-D warnings)/test green (55 tests)

src/lib.rs

@@ -0,0 +1,11 @@
+//! Rampart — универсальная платформа сетевой защиты (L3/L4/L7).
+pub mod cli;
+pub mod config;
+pub mod engine;
+pub mod filter;
+pub mod manager;
+pub mod metrics;
+pub mod protocol;
+pub mod store;
+pub mod traffic;
+pub mod xdp;