refactor(x): per-process scratch dirs, Ludic ports of the LSP test and Forgejo release

- every scratch file lives in `$TMPDIR/x_<pid>/` (tmp_dir/tmp_path in
  prelude.ludic), removed by main's new dispatch() → tmp_cleanup();
  X_KEEP_TMP=1 keeps it. `x test` and `x check-*` may now run together.
- `x test-lsp` (tools/x/lsp_test.ludic) replaces tools/test-lsp.py: the
  whole request stream is framed into one stdin file, the server runs to
  `exit`, and the response stream is parsed back by request id; adds a
  check that ludicc's own error is published on save
- tools/x/forgejo.ludic replaces tools/ci/forgejo_release.py (curl with a
  0600 header file; the token is no longer on the command line;
  LUDIC_FORGEJO_API for forks)
- `x docs-palette --check` regenerates into scratch and compares, so the
  drift guard judges the working tree rather than git HEAD; the generator
  no longer emits a trailing blank line the formatter rejects
- `x test-tools`: exit 2 from test-lsp / test-grammar.js is a visible
  skip, never a pass; the widget-prop test uses the `id: Root` syntax
- tools/test-grammar.js: current vocabulary (property/model/handler/
  prefab/scene/event/become/@Queries), LUDIC_NODE_MODULES, exit 2 on skip
- tools/atlas.ludic rewritten in the current language (it did not compile)
- operators.ludic / os.ludic registered in the suite
- json.ludic: j_quote() writer helper

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

tools/x/build.ludic

@@ -56,8 +56,8 @@ function cmd_app() -> int {
     if (a == "--headless") { mode = 2 }
     else if (a == "--windowed") { mode = 1 }
     else if (a == "--save-temps") { save = true }
-    else if (a[0] != 45) { src = a }        # 45 = '-', so skip other flags
-    ai = ai + 1
+    else if (a[0] != '-') { src = a }        # 45 = '-', so skip other flags
+    ai += 1
   }
   if (src == null) { err("usage: x app <file.ludic> [--headless] [--save-temps]\n"); return 1 }
   let name = capture_line(`basename {src} .ludic`)