Compose the void marker with the readonly glyph: wipe! =! ->

[shreeve]

Summary

save! = -> defines a void function (no implicit return, no trailing-loop comprehension). x =! v is a readonly binding. They now compose:

wipe! =! (xs) ->
  for x in xs
    x.reset()

export flush! =! -> drain()

emits const wipe = (function(xs) { for (...) {...} return; }); and export const flush = .... Previously both forms were a parse error.

Changes

• Lexer: DAMMIT directly before =! mints VOID_MARKER, as it already did before =.
• Grammar: void-readonly rows beside void-assign in Assign and ExportAssign over the same RHS shapes; readonly kind gains the voidMarker role; parser regenerated under the manifest gate, no conflict drift.
• Emitter: dispatches through the readonly path and registers the value as void. n! =! 5 is rejected with the void-marker error; wipe = 2 after the definition is rejected as a readonly write. TS face declares it readonly.
• Editor grammars: VS Code and Vim readonly-name rules admit the bang and scope it as the void marker; lockstep test pins captures against compiled output. highlight.js needs no change.
• Tests: battery rows in assignment.rip and sweep.rip (the wrapped/indented pins reduce the next-line RHS productions the coverage gate requires); void-marker lane and corpus gain the =! case. Corpus: only voidmarker.* regenerate.

Verification

• bun run test:rip: 3284 pass, 0 fail
• bun test test/toolchain: 661 pass (production coverage, kinds registry, generated-parser gates)
• bun run corpus: stable after regeneration
• bun run test:all: 26 lanes, 9895 tests passed
• dist/@rip regenerated under Bun 1.4.0