Wrap startup in try/except with file log + Tk messagebox

--noconsole exes silently exit on import-time errors, so when v0.3.2
crashed during startup the user just saw nothing happen. This wrapper:
- Catches BaseException at module-import and main() level
- Writes traceback to %LOCALAPPDATA%/sephiria_inv/startup.log
- Pops a Tk messagebox-equivalent window with the traceback
- Falls back gracefully if Tk itself is unavailable

Also build with --console (no --noconsole) so prints/tracebacks are
visible in real time. Once we know what is failing we can re-enable
windowed mode.

run.py

@@ -1,6 +1,80 @@
-"""PyInstaller entry shim."""
+"""PyInstaller entry shim.
+
+Wrapped in a top-level try/except so any startup failure is written to
+%LOCALAPPDATA%\\sephiria_inv\\startup.log and surfaced to the user via a
+Tk messagebox when possible. Without this wrapper, --noconsole builds
+exit silently on import-time errors and the user sees "nothing happens".
+"""
+
+from __future__ import annotations
+
+import os
+import sys
+import traceback
+from datetime import datetime
+
+
+def _log_path() -> str:
+    base = os.environ.get("LOCALAPPDATA") or os.path.expanduser("~")
+    folder = os.path.join(base, "sephiria_inv")
+    try:
+        os.makedirs(folder, exist_ok=True)
+    except OSError:
+        folder = os.path.dirname(os.path.abspath(sys.argv[0])) or "."
+    return os.path.join(folder, "startup.log")
+
+
+def _write_log(msg: str) -> str:
+    path = _log_path()
+    try:
+        with open(path, "a", encoding="utf-8") as fh:
+            fh.write(f"\n=== {datetime.now().isoformat()} ===\n{msg}\n")
+    except OSError:
+        pass
+    return path
+
+
+def _show_error(title: str, body: str) -> None:
+    try:
+        import tkinter as tk
+        from tkinter import scrolledtext
+        root = tk.Tk()
+        root.title(title)
+        root.geometry("760x420")
+        txt = scrolledtext.ScrolledText(root, wrap="word")
+        txt.pack(fill="both", expand=True)
+        txt.insert("1.0", body)
+        tk.Button(root, text="Close", command=root.destroy).pack(pady=4)
+        root.mainloop()
+    except Exception:
+        # Tk itself is broken; nothing we can show.
+        pass
+
+
+def _main() -> int:
+    try:
+        from sephiria_inv.__main__ import main
+    except BaseException:
+        tb = traceback.format_exc()
+        log = _write_log("IMPORT FAIL\n" + tb)
+        _show_error(
+            "sephiria_inv: import failed",
+            f"Failed to import sephiria_inv.__main__\n\nLog: {log}\n\n{tb}",
+        )
+        return 11
+    try:
+        return int(main() or 0)
+    except SystemExit:
+        raise
+    except BaseException:
+        tb = traceback.format_exc()
+        log = _write_log("RUNTIME FAIL\n" + tb)
+        _show_error(
+            "sephiria_inv: runtime error",
+            f"Crashed during main()\n\nLog: {log}\n\n{tb}",
+        )
+        return 12
 
-from sephiria_inv.__main__ import main
 
 if __name__ == "__main__":
-    raise SystemExit(main())
+    raise SystemExit(_main())

sephiria_inv/gui.py

@@ -398,7 +398,7 @@ class ScreenshotFrame(ttk.Frame):
     def __init__(self, master, on_confirmed) -> None:
         super().__init__(master, padding=6)
         self.on_confirmed = on_confirmed
-        self.slot_var = master.master.slot_var  # type: ignore[attr-defined]
+        self.slot_var = master.winfo_toplevel().slot_var  # type: ignore[attr-defined]
         self.image: Optional[Image.Image] = None
         self.bbox: Optional[Tuple[int, int, int, int]] = None
         self.cells: List[CellResult] = []