consolidate build scripts, reorganize source into src/ directory, fix favicon injection

src/shims/path.js

@@ -0,0 +1,18 @@
+// Path shim. delegates to path-browserify (bundled via esbuild alias)
+// Configured for posix mode since vault paths are normalized to forward slashes.
+
+import pathBrowserify from "path";
+
+const _origBasename = pathBrowserify.basename;
+
+export const pathShim = {
+  ...pathBrowserify,
+  basename(p, ext) {
+    // Vault root "/" should return the vault name for display purposes
+    if (p === "/" && window.__currentVaultId) {
+      return window.__currentVaultId;
+    }
+
+    return _origBasename(p, ext);
+  },
+};