fix: add path qualification to Files app pathbar

kernel/src/Api/BuildNo.hpp

@@ -12,4 +12,4 @@
 
 #pragma once
 
-#define MONTAUK_BUILD_NUMBER 42
+#define MONTAUK_BUILD_NUMBER 43

programs/src/desktop/apps/filemanager/navigation.cpp

@@ -164,6 +164,42 @@ void filemanager_cancel_pathbar(FileManagerState* fm) {
     fm->pathbar_editing = false;
 }
 
+// True if `path` begins with a "N:/" volume prefix (one or more digits then ":/").
+static bool filemanager_has_volume_prefix(const char* path) {
+    int i = 0;
+    while (path[i] >= '0' && path[i] <= '9') i++;
+    return i > 0 && path[i] == ':' && path[i + 1] == '/';
+}
+
+// Resolve a user-typed path into a fully-qualified "N:/..." path. Paths without
+// a volume number (e.g. "/os" or "os") are drive-relative; the kernel resolves
+// them against drive 0, but filemanager_read_dir strips a drive-root-relative
+// prefix, so an unqualified path would leave the returned basenames with their
+// full sub-path. Qualify it here so the prefix stripping matches. The drive of
+// the current location is preferred, falling back to drive 0.
+static void filemanager_qualify_path(FileManagerState* fm, char* out, int out_max) {
+    const char* in = fm->pathbar_buf;
+    if (filemanager_has_volume_prefix(in)) {
+        montauk::strcpy(out, in);
+        return;
+    }
+
+    char drive[8] = "0";
+    if (filemanager_has_volume_prefix(fm->current_path)) {
+        int i = 0;
+        while (fm->current_path[i] >= '0' && fm->current_path[i] <= '9' && i < 6) {
+            drive[i] = fm->current_path[i];
+            i++;
+        }
+        drive[i] = '\0';
+    }
+
+    montauk::strcpy(out, drive);
+    str_append(out, ":", out_max);
+    if (in[0] != '/') str_append(out, "/", out_max);
+    str_append(out, in, out_max);
+}
+
 void filemanager_commit_pathbar(FileManagerState* fm) {
     fm->pathbar_editing = false;
     if (fm->pathbar_len == 0) {
@@ -171,7 +207,7 @@ void filemanager_commit_pathbar(FileManagerState* fm) {
         filemanager_push_history(fm);
         return;
     }
-    montauk::strcpy(fm->current_path, fm->pathbar_buf);
+    filemanager_qualify_path(fm, fm->current_path, sizeof(fm->current_path));
     filemanager_read_dir(fm);
     filemanager_push_history(fm);
 }