fix: skip path: null entries in cross-reference

Files with explicit path: null are UI-imported (Dolphin NAND,
Hatari cartridge) and not resolvable by pack placement. Skip
them in find_undeclared_files and cross_reference. Also add
desc.dat (SDLPAL fan-made descriptions) to data/. 149/149 OK.

database.json

@@ -1,5 +1,5 @@
 {
-  "generated_at": "2026-03-29T00:20:22Z",
+  "generated_at": "2026-03-29T05:25:34Z",
   "total_files": 7625,
   "total_size": 9746817953,
   "files": {

scripts/cross_reference.py

@@ -156,6 +156,10 @@ def cross_reference(
             if "<" in fname or ">" in fname:
                 continue
 
+            # Skip UI-imported files with explicit path: null (not resolvable by pack)
+            if "path" in f and f["path"] is None:
+                continue
+
             # Skip standalone-only files
             file_mode = f.get("mode", "both")
             if file_mode == "standalone":

scripts/verify.py

@@ -318,6 +318,9 @@ def find_undeclared_files(
             # Skip pattern placeholders (e.g., <user-selected>.bin)
             if "<" in fname or ">" in fname or "*" in fname:
                 continue
+            # Skip UI-imported files with explicit path: null (not resolvable by pack)
+            if "path" in f and f["path"] is None:
+                continue
             # Mode filtering: skip files incompatible with platform's usage
             file_mode = f.get("mode")
             if file_mode == "standalone" and not is_standalone: