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)

xdp/config.h

@@ -1,31 +0,0 @@
-#ifndef RAMPART_CONFIG_H
-#define RAMPART_CONFIG_H
-
-// ⚙️ Runtime configurable globals (patched by Rust loader)
-// These are volatile const — compiler replaces reads with immediate values
-// after loader writes to .rodata section
-
-// ── Port range ──
-static volatile const __u16 G_START_PORT = 25565;
-static volatile const __u16 G_END_PORT   = 25570;
-
-// ── SYN throttle ──
-static volatile const __u32 G_SYN_HIT_COUNT      = 10;    // max SYNs / window
-static volatile const __u64 G_SYN_WINDOW_NS       = 3000000000ULL; // 3 sec
-static volatile const __u64 G_SYN_BAN_DURATION_NS = 60000000000ULL; // 60 sec
-
-// ── Idle timeouts ──
-static volatile const __u64 G_CONNTRACK_IDLE_NS   = 30000000000ULL; // 30 sec
-static volatile const __u64 G_PLAYER_IDLE_NS      = 120000000000ULL; // 120 sec
-
-// ── Blacklist default ban duration ──
-static volatile const __u64 G_BAN_DURATION_NS     = 300000000000ULL; // 5 min
-
-// ── Max out-of-order packets before dropping connection ──
-static volatile const __u8 G_MAX_OUT_OF_ORDER = 4;
-
-// ── Feature flags ──
-static volatile const __u8 G_FEATURE_SYN_THROTTLE  = 1;
-static volatile const __u8 G_FEATURE_EVENTS        = 1;
-
-#endif /* RAMPART_CONFIG_H */