fix: resolve iOpenPod import conflict by removing src/ from sys.path during iop imports

iTunesDB_Writer's internal 'from ipod_device import ChecksumType' was resolving
to our local src/ipod_device.py instead of iOpenPod's version, even with
iop path at sys.path[0] (Python 3.14 import resolution quirk).

Now temporarily removes project src/ from sys.path during iOpenPod imports,
restoring it afterwards. The validated flow: main.py imports local ipod_device
first, then _import_iop evicts and replaces it when iPod tab is used.

src/ipod_nano7_db.py

@@ -88,19 +88,30 @@ def _import_iop(module_name: str):
         return _IOP_CACHE[module_name]
 
     if not _IOP_READY:
-        # Evict local shadows ONCE so iOpenPod modules resolve correctly.
         sys.modules.pop("ipod_device", None)
         _IOP_READY = True
         logger.debug("iOpenPod boot: evicted local ipod_device")
 
+    src_paths = [p for p in sys.path if p.endswith('/src') or p == 'src']
+    for p in src_paths:
+        sys.path.remove(p)
+
     had_iop = _IOP_ROOT in sys.path
     if not had_iop:
         sys.path.insert(0, _IOP_ROOT)
+        importlib.invalidate_caches()
+
     try:
         mod = importlib.import_module(module_name)
     finally:
+        for p in src_paths:
+            if p not in sys.path:
+                sys.path.insert(0, p)
         if not had_iop:
-            sys.path.remove(_IOP_ROOT)
+            try:
+                sys.path.remove(_IOP_ROOT)
+            except ValueError:
+                pass
 
     _IOP_CACHE[module_name] = mod
     return mod