go: lex.sx — operator-set audit + tilde; PHASE 1 COMPLETE + 6 tests [proposes-lex]

Adds the missing tilde operator '~' (Go 1.18+ generics type-set
constraint, e.g. 'interface { ~int | ~float64 }') to the longest-match
operator table. Adds an exhaustive 'op-audit:' test block covering
every Go operator/punctuation token by category — arithmetic +
assignment, bitwise + assignment, comparison + logical, decls /
arrows / variadic / inc-dec, punctuation, and tilde.

Phase 1 (tokenizer) is now complete. Two kit gaps surfaced and logged
in plans/go-on-sx.md Blockers for the substrate maintainer / next
statically-typed guest loop:

  * lib/guest/lex.sx lacks lex-oct-digit? / lex-bin-digit?
    (we rolled local gl-* equivalents for 0o.. and 0b.. literals).
  * lib/guest/lex.sx lacks a table-driven longest-prefix operator
    matcher; our gl-match-op is a 25-clause cond ladder. Rust/Swift/TS
    will each hit the same shape with 50+ ops apiece.

lex 129/129. Phase 2 (parser) next.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

lib/go/tests/lex.sx

@@ -229,30 +229,60 @@
   "punct: comma colon dot"
   (tok-values ", : .")
   (list "," ":" "." nil))
+(go-test
+  "op-audit: tilde (generics type-set)"
+  (tok-values "~int")
+  (list "~" "int" "\n" nil))
+(go-test
+  "op-audit: all arithmetic + assignment"
+  (tok-values "+ - * / % += -= *= /= %=")
+  (list "+" "-" "*" "/" "%" "+=" "-=" "*=" "/=" "%=" nil))
+(go-test
+  "op-audit: all bitwise + assignment"
+  (tok-values "& | ^ << >> &^ &= |= ^= <<= >>= &^=")
+  (list "&" "|" "^" "<<" ">>" "&^" "&=" "|=" "^=" "<<=" ">>=" "&^=" nil))
+(go-test
+  "op-audit: all comparison + logical"
+  (tok-values "== != < > <= >= && || !")
+  (list "==" "!=" "<" ">" "<=" ">=" "&&" "||" "!" nil))
+(go-test
+  "op-audit: assign / decls / arrows / variadic / inc-dec"
+  (tok-values "= := <- ++ -- ...")
+  (list "=" ":=" "<-" "++" "--" "..." nil))
+
+;; ── short program ─────────────────────────────────────────────────
+(go-test
+  "op-audit: punctuation"
+  (tok-values "( ) [ ] { } , . :")
+  (list "(" ")" "[" "]" "{" "}" "," "." ":" nil))
 (go-test
   "ASI: after ident at newline"
   (tok-types "x\ny")
   (list "ident" "semi" "ident" "semi" "eof"))
 (go-test "ASI: after int" (tok-types "42\n") (list "int" "semi" "eof"))
+
+;; ── report ────────────────────────────────────────────────────────
 (go-test "ASI: after float" (tok-types "3.14\n") (list "float" "semi" "eof"))
+
 (go-test
   "ASI: after string"
   (tok-types "\"hi\"\n")
   (list "string" "semi" "eof"))
+
 (go-test "ASI: after rune" (tok-types "'a'\n") (list "rune" "semi" "eof"))
 
-;; ── short program ─────────────────────────────────────────────────
 (go-test
   "ASI: after )"
   (tok-types "f()\n")
   (list "ident" "op" "op" "semi" "eof"))
+
 (go-test
   "ASI: after ]"
   (tok-types "x[0]\n")
   (list "ident" "op" "int" "op" "semi" "eof"))
+
 (go-test "ASI: after }" (tok-types "{}\n") (list "op" "op" "semi" "eof"))
 
-;; ── report ────────────────────────────────────────────────────────
 (go-test "ASI: after ++" (tok-types "i++\n") (list "ident" "op" "semi" "eof"))
 
 (go-test