Phase 7a: bitwise operators & | ^ << >> ~ (retire band/bor/shl/…)

First step of the "stop feeling like C" pass. Bitwise ops were functions
(`band(x, MASK)`, `shl(a, 3)`); they are now real operators:

  band -> &   bor -> |   bxor -> ^   shl -> <<   shr -> >>   bnot -> ~

Precedence is Go-style so the C footgun is gone: `<<`/`>>`/`&` bind like `*`,
`|`/`^` like `+`, both tighter than comparison — `flags & MASK == 0` parses as
`(flags & MASK) == 0`. `>>` is logical (lshr), matching the old `shr`.

Mechanics: lexer tokenizes `<< >> & | ^ ~`; p_mul takes `<< >> &`, p_add takes
`| ^`, p_unary takes `~`; emit_bin routes them through the existing int arith
path (arith_code gains and/or/xor/shl/lshr) and E_UN handles `~`. The six
intrinsics are deleted.

Delivered as two reseeds: (A) add the operators keeping the intrinsics, (B)
migrate every call site to operator form (85 lines across compiler + runtime,
via a balanced-paren call->operator script; two multi-line big-endian reads in
image/truetype done by hand) and delete the intrinsics. Vocabulary drops the six
from LUDIC_INTRINSICS (ludic_syntax.h, grammar, LudicTokens.kt) and the grammar
gains a bitwise-operator rule. LANGUAGE.md precedence table rewritten.

Reseeded (21724 lines); C-free fixpoint holds; goldens byte-identical (the PNG
and TrueType decoders lean on these ops); 17/17; vocab + doc-fences clean.

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

selfhost/main.ludic

@@ -148,6 +148,6 @@ entry {
   # run mode: execute the binary we just built and forward its exit code
   if run {
     let st = os_system(out)
-    os_exit(band(shr(st, 8), 255))
+    os_exit(((st >> 8) & 255))
   }
 }