Add .gitattributes routing *.vsix through Git LFS and convert the committed
extension vsix to an LFS pointer. Keeps the reproducible build artifact in the
repo without growing normal history on each rebuild. Future-only — existing
vsix blobs remain in history (a `git lfs migrate` rewrite would be needed to
purge those, deferred since origin/master is shared).
Two post-stream follow-ups flagged in CHECKPOINT-EXTERN-EXPORT.md, plus a
reproducible vscode-extension packaging setup:
- parser: drop the vestigial `RuntimeClassPrefix.is_extern` field and
`parseRuntimeClassDecl`'s `is_extern` param. Always false since the
`#foreign` token was deleted; the postfix `extern`/`export` keyword is the
sole reference-vs-define decider. No behavior change (644 corpus / 442 unit).
- vscode grammar: highlight `extern`/`export` as `storage.modifier.sx`.
- vscode packaging: declare `@vscode/vsce` as a devDep + add `package` /
`vscode:prepublish` scripts so the vsix rebuilds reproducibly (was an
ambient tool). Add repository/homepage/bugs (Gitea), icon (swipelab logo,
256x256), galleryBanner, README with cover banner. Rebuilt the vsix.
git-mv the 10 foreign-named example families to extern/runtime-class names + update
every #import/#include/#source ref, stale comment ref, and the 1172 stderr snapshot
(path + 'extern symbol' message). Renames: 0729…-foreign→…-extern, 1172-diagnostics-
foreign-symbol-conflict→…-extern-symbol-conflict, 1205/1207 ffi-foreign-global→
ffi-extern-global, 1216/1217 ffi-…-foreign-(in-method|result-chain)→…-extern-…,
1219-ffi-foreign→1219-ffi-extern, 1306 objc-foreign-class-chained→objc-runtime-class-
chained, 1318 objc-property-foreign→objc-property-extern-class. DEDUP: deleted
1218-ffi-foreign-cvariadic (identical to 1229-ffi-extern-cvariadic; updated 1229's
twin ref) + the orphaned 1620 dir. Also purged editors/vscode tmLanguage (#foreign
dropped from the directive highlighter) + 1220.h/issues-0030.sx comment refs. Suite
green (644 corpus / 443 unit, 0 failed).
VSCode disables the breakpoint gutter for a language unless an extension
declares breakpoints are valid for it. The sx extension registered the
language but never contributed breakpoints, so clicking the gutter in a
.sx file did nothing. Add the breakpoints contribution so users can set
breakpoints in .sx files without the per-workspace
debug.allowBreakpointsEverywhere hack.