build(x): stop printing a clang warning on every build

Each clang invocation the task runner makes emitted

    warning: overriding the module target triple with arm64-apple-macosx15.5.0

four times per `x build`, with nothing for anyone to act on. `cc()` now passes
-Wno-override-module, the same flag ludicc already passes for its own link.

The comment in selfhost/main.ludic explaining that flag had it backwards — it
claimed "our IR carries an explicit target triple", when the emitted IR names
no triple at all, which is precisely why clang substitutes the host's and
warns. Corrected. No IR changes, so the seed is untouched.

Also adds .claude/launch.json entry for previewing the generated docs locally.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

selfhost/main.ludic

@@ -157,8 +157,9 @@ entry {
 
   # clang twice: assemble the IR, then link. A windowed build adds the macOS
   # platform layer and the Cocoa framework.
-  # -Wno-override-module: our IR carries an explicit target triple, which clang
-  # would otherwise warn about on every build.
+  # -Wno-override-module: the emitted IR carries no target triple, so clang
+  # substitutes the host's and warns about it on every single build. There is
+  # nothing to act on — the host default is exactly what we want — so it is off.
   var cmd = `{cc} -O2 -Wno-override-module {ll}`
   if g_windowed {
     let cocoa = join_path(home, "runtime/native/cocoa.ll")