go: Phase 7 foundation — generics syntax through parser/typer/eval [shapes-static-types-bidirectional]

gp-parse-type-params consumes the optional [NAMES CONSTRAINT, ...]
clause after a func name. AST stays backward-compatible: 5-slot
func-decl when no [...] is present, 6-slot when it is.

Typer binds each type-param name as (:ty-param NAME CONSTRAINT) so
body's (:ty-name "T") references resolve. Eval is type-erasing —
ignores type info, dispatches by name + arity.

10 new tests: parse (3), types (5), eval (2). Total 527/527.

Shape: the field binding-group from the canonical kit now feeds
6 consumers (struct fields, var-decls, const-decls, params,
receivers, type-params). Confirms it as a TRUE cross-deliverable
shape — sister-plan diary documents the 5 roles binding-groups
take and why the kit should expose ONE parser + pluggable validators.

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

lib/go/scoreboard.json

@@ -1,12 +1,12 @@
 {
   "language": "go",
-  "total_pass": 517,
-  "total": 517,
+  "total_pass": 527,
+  "total": 527,
   "suites": [
     {"name":"lex","pass":129,"total":129,"status":"ok"},
-    {"name":"parse","pass":176,"total":176,"status":"ok"},
-    {"name":"types","pass":72,"total":72,"status":"ok"},
-    {"name":"eval","pass":100,"total":100,"status":"ok"},
+    {"name":"parse","pass":179,"total":179,"status":"ok"},
+    {"name":"types","pass":77,"total":77,"status":"ok"},
+    {"name":"eval","pass":102,"total":102,"status":"ok"},
     {"name":"runtime","pass":40,"total":40,"status":"ok"},
     {"name":"stdlib","pass":0,"total":0,"status":"pending"},
     {"name":"e2e","pass":0,"total":0,"status":"pending"}