Phase 2: enforce statement separators (Rule B)

The parser now requires a newline or ';' between statements (block() in
selfhost/parse.ludic); two statements may no longer sit adjacent with only
spaces. Also fixed if-without-else swallowing its trailing separator.

Migration: tools/ludic-tools/migrate_separators.c inserts ';' at statement
boundaries corpus-wide (examples, runtime, 25 self-host fragments, ~1100
boundaries). Verified semantically identical — the migrated compiler compiles
itself to IR byte-identical to the pre-migration seed, and every golden game
renders identically. Reseeded to the strict compiler; C-free fixpoint holds;
test.sh 14/14.

Docs: Rule B documented in LANGUAGE.md; BOOTSTRAP.md R1 + stale fences updated;
check-docs green across all docs. Fixed a multi-line string literal in
emit_expr.ludic (byte-identical \n escape) that the C toolchain lexer mis-lexes.

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

selfhost/tests/control.ludic

@@ -1,12 +1,12 @@
 game T {
-  fn fib(n: int) -> int { if n < 2 { return n }  return fib(n-1) + fib(n-2) }
+  fn fib(n: int) -> int { if n < 2 { return n };  return fib(n-1) + fib(n-2) }
   main {
     print_int(fib(10))                 # 55
     let s = 0
-    for i in 0 .. 10 { if i == 5 { break }  if i % 2 == 0 { continue }  s = s + i }
+    for i in 0 .. 10 { if i == 5 { break };  if i % 2 == 0 { continue };  s = s + i }
     print_int(s)                       # 1+3 = 4
-    let i = 0  let t = 0
-    while true { i = i + 1  if i > 5 { break }  t = t + i }
+    let i = 0;  let t = 0
+    while true { i = i + 1;  if i > 5 { break };  t = t + i }
     print_int(t)                       # 15
     if false and (1/0 == 0) { print_int(999) } else { print_int(1) }   # short-circuit: no div by zero
   }

selfhost/tests/match_bits.ludic

@@ -1,6 +1,6 @@
 game T {
   fn classify(c: int) -> int {
-    match c { 65, 66 => { return 1 }  67 => { return 2 }  _ => { return 9 } }
+    match c { 65, 66 => { return 1 };  67 => { return 2 };  _ => { return 9 } }
     return 0
   }
   main {