Networking N2–N6, and a fully C-free toolchain

Implement the rest of NETWORKING-DESIGN.md (N2–N6) and eliminate every
`.c` file from the repo. clang remains only the LLVM-IR assembler; no C
is compiled anywhere.

Networking (selfhost/emit_net.ludic + parser/emit changes):
- N2 @Sync: per-model serialize/apply + by-kind dispatchers; POD-scalar
  compile error and empty-participation warning; selective replication.
- N3 @Owned: @L_owner array + owner/set_owner/is_owner; owners snapshot.
- N4 @ToServer/@ToClients remote events: framed net_send + net_pump re-emit.
- N5 @Server/@Predicted role guards + drivable sim (tick_fixed/tick_render,
  entry-owns-the-loop).
- Built-in loopback transport so multiplayer runs with zero foreign code;
  extern fn net_send/net_poll still overrides it for a real socket.
- N6 blessed runtime (examples/net_rt.ludic) + end-to-end demo (net_demo).
- Fix: llty("entity") is now i32 (entities are i32 handles), so let e = self().

C elimination:
- Networking + foreign-mod-ABI tests rewritten as self-contained pure-Ludic
  programs (examples/net_*, world_*, mod_events, scoped); tests/ removed.
- Reflection ABI exposed to Ludic as world_* builtins (Ludic-to-Ludic modding).
- Formatter rewritten C→Ludic: tools/ludic-tools/fmt.ludic.
- Language server rewritten C→Ludic: tools/ludic-tools/lsp.ludic (lexer, index
  parser, cross-file workspace resolver, JSON, all LSP handlers).
- Obsolete migrate_*.c codemods deleted; ludic_syntax.h kept as vocabulary data.

Suites: ./test.sh 44/44, ./tools/test-tools.sh 28/28 (LSP 42/42), fixpoint holds.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tools/editors/jetbrains/src/main/kotlin/io/ludic/ide/LudicTokens.kt

@@ -42,15 +42,15 @@ object LudicTokens {
 object LudicVocabulary {
     val DECL = setOf(
         "program", "import", "property", "model", "enum", "ui",
-        "const", "var", "fn", "extern", "handler", "entry"
+        "const", "var", "fn", "extern", "handler", "entry", "event", "scene"
     )
     val CLAUSE = setOf(
-        "phase", "query", "on"
+        "phase", "query", "on", "cancellable", "public", "layer", "start"
     )
     val STMT = setOf(
         "let", "return", "if", "else", "while", "for", "in", "spawn", "despawn",
         "enable", "disable", "match", "machine", "state", "become", "where",
-        "and", "or", "not", "break", "continue", "new"
+        "and", "or", "not", "break", "continue", "new", "emit", "cancel"
     )
     val PRIMITIVES = setOf("int", "fixed", "bool", "entity", "str", "ptr", "byte", "words", "fixeds", "ptrs", "void")
     val PHASES = setOf("Start", "Input", "FixedUpdate", "Update", "LateUpdate", "Render")