parse_statement parses every spec 7 form (assignment, call, if/else,
while, for/to/step, return, print, delete) and requires the line to end
after it. Expressions use precedence climbing over spec 8's levels: binary
operators left associative, unary not and - nesting rightwards, postfix
member access, calls, and indexing tightest. A syntax error is reported in
pass 1, unwinds to the statement, and skips the line; E03-S02's name,
member, and access checks now run from the parser in pass 2, replacing the
token scan. Expression nesting is bounded at 16 levels (E225).

Verified in x128: 31 fixtures, including the two statement fixtures that
were pending since E03-S01, a postfix trace golden for precedence and
associativity (both mutations caught), every statement form, and 15
independent syntax errors with recovery. Lowest stack pointer $A7. New
diagnostics E038-E042 and E225. The demo passes; its Vim typing is slowed
to 200 ms per key after one doubled keystroke.

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

scripts/demo-write-check.ps1 types each demo program into the Vim clone
on x64sc (fresh copy of vim/work.d81), confirms the saved SEQ file matches
its ASCII mirror, then runs demo/n8check.s on x128: a DEMO driver (not
N128C) that asks for a file name and runs the current front end (source
reader, lexer, names, parser) with on-screen diagnostics and NAME.ERR.
good.n8 checks clean; bad.n8 reports its four intended errors.

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