wasm vfs path fix

wasi-runtime/runtime.js

@@ -301,6 +301,12 @@ if (!wasmUrl) {
 // EnableWasiBrowserRuntime) into an in-memory VFS so wasi-libc's file
 // syscalls work against them. Browser builds otherwise can't open assets
 // shipped alongside the .wasm — sync XHR is too deprecated to rely on.
+//
+// Manifest entries are relative paths under the bin dir (the layout
+// `cfg.assets` produces — e.g. "assets/Inter.ttf",
+// "mods/3DForts_Base/foo.cmesh"). We fetch each at its full path but
+// key the VFS by basename so `path_open`'s basename-reduction can find
+// it regardless of the C++ side's cwd or prefix.
 const vfs = new Map();
 try {
     const manifestResp = await fetch("files.json");
@@ -308,8 +314,12 @@ try {
         const names = await manifestResp.json();
         await Promise.all(names.map(async (name) => {
             const r = await fetch(name);
-            if (r.ok) vfs.set(name, new Uint8Array(await r.arrayBuffer()));
-            else console.warn(`[wasi] failed to preload ${name}: HTTP ${r.status}`);
+            if (!r.ok) {
+                console.warn(`[wasi] failed to preload ${name}: HTTP ${r.status}`);
+                return;
+            }
+            const base = name.split(/[\\/]/).filter(Boolean).pop() || name;
+            vfs.set(base, new Uint8Array(await r.arrayBuffer()));
         }));
     }
 } catch (e) {