parser.s runs two passes over the cached source. Pass 1 parses interfaces,
classes (implements lists, fields, method headers), and the one program,
records top-level types in a bank-1 table, tracks method/program/if/while/
for blocks, checks duplicate locals, and reports syntax, ordering, and
duplicate errors with line-level recovery. Pass 2 reports type references
that name no declared type, so forward references are legal.

Verified in x128 against 24 fixtures through the real ERR files: 7/7
accepted, 10/12 rejected grammar fixtures at their sidecar positions
(line_cont and multi_stmt are statement-level, pending E03-S03), and five
parser fixtures matching their complete diagnostic lists. A pass-order
mutation is caught. D121 (proposed): method names may be keywords, as
spec 5.1's `method print()` requires.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>