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/selfhost.ludic

@@ -79,7 +79,7 @@ function write_selfhost_src(outpath: pointer) -> bool {
     let s = read_file(frags[i])
     if (s != null) { file_write(f, s, len(s)) }
     file_write(f, "\n", 1)
-    i = i + 1
+    i += 1
   }
   let ftr = "}\n"
   file_write(f, ftr, len(ftr))
@@ -131,11 +131,11 @@ function cmd_sh_compile(shbin: pointer, in: pointer, outbin: pointer) -> int {
 # strips the dead windowing branches so a headless link needs no win_* defs.
 
 # the quiet core, reused by the test suites; returns true on success. On failure
-# the self-host/link diagnostics are left in /tmp/x_gb.err.
+# the self-host/link diagnostics are left in tmp_path("gb.err").
 function game_build_ok(shbin: pointer, game: pointer, outbin: pointer) -> bool {
   let ll = `{outbin}.ll`
-  if not shq(`{shbin} {game} > {ll} 2>/tmp/x_gb.err`) { return false }
-  if not shq(`{cc()} -O2 {ll} -o {outbin} 2>/tmp/x_gb.err`) { return false }
+  if not shq(`{shbin} {game} > {ll} 2>{tmp_dir()}/gb.err`) { return false }
+  if not shq(`{cc()} -O2 {ll} -o {outbin} 2>{tmp_dir()}/gb.err`) { return false }
   run(`rm -f {ll}`)
   return true
 }
@@ -144,7 +144,7 @@ function game_build_ok(shbin: pointer, game: pointer, outbin: pointer) -> bool {
 function cmd_game_build(shbin: pointer, game: pointer, outbin: pointer) -> int {
   if game_build_ok(shbin, game, outbin) { print(`built {outbin}`); return 0 }
   print("build failed:")
-  out(capture("grep -i error /tmp/x_gb.err | head -5"))
+  out(capture(`grep -i error {tmp_dir()}/gb.err | head -5`))
   return 1
 }