📝 Sweep doc and formatter drift

README named --experimental-strip-types, which was renamed to
--strip-types. Document the current flag only.

The extension recommendations list is unchanged, but the VSCode section
undercounted it and now matches extensions.json. The per-language
formatter blocks in .vscode/settings.json stay (they keep a user's
local formatter settings from overriding the project's) and gain the
JSX/TSX language ids to match what oxfmt and the lefthook glob cover.

backlog.tasks

@@ -48,9 +48,9 @@ Setup:
 ☐ Resolve sourcemap sources for consumers
     - `dist/*.map` `sources` are `../src/*.ts`, but `src` is not in `files`, so debuggers get missing sources
     ☐ Ship `src`, or disable `sourceMap`/`declarationMap` for the published artifact
-☐ Sweep doc/formatter drift before v1.0
-    ☐ README says `--experimental-strip-types`; scripts use `--strip-types`
-    ☐ `.vscode/settings.json` bundles `[markdown]`/`[yaml]` oxfmt formatters separately from `.oxfmtrc.json`'s `ignorePatterns` — align
+✔ Sweep doc/formatter drift before v1.0 @done
+    ✔ README says `--experimental-strip-types`; scripts use `--strip-types` @done
+    ✔ `.vscode/settings.json` bundles `[markdown]`/`[yaml]` oxfmt formatters separately from `.oxfmtrc.json`'s `ignorePatterns` — align @done
 ✔ Document branching model @done
     ✔ Describe branching model: when to branch, base branch, naming @done
     ✔ Clarify release workflow: who pushes `main`, CI as post-merge gate, drop PR usage @done (9/8/2026, 2:54:32 PM)