PyCForge editor fixes — Windows acceptance

For your existing v1.2.0 installation, use the 1.2.1 wheel:

1. Save your Python files and close PyCForge. In the directory containing the
   downloaded wheel, run:
   py -m pip install --upgrade .\pycforge-1.2.1-py3-none-any.whl
   py -m pycforge.ide
   Confirm the title bar, startup and Help > About show 1.2.1.
   About must no longer show the Ting Shadow / Advisory badge.

   The separate 1.1.11 wheel updates the recent 1.1.10 conversion line. To test
   that line instead, use its wheel filename in the install command. It retains
   its runtime conversion features; the PCFC11 branch remains separate.

2. Create a module with:
   def main() -> int:
       return 0
   Transpile it and leave Generated C visible. Save the source, close its final
   tab, and confirm Source Bundle is empty. New Module and Open Python must
   both work. Repeat with the C panel shown and hidden.

3. Open two Python modules containing multi-line functions. Switch repeatedly
   between tabs. Their own fold arrows should appear. Click arrows to fold and
   reveal each function. Repeat with the split source view enabled.

4. Use this syntactically valid unsupported function to reject conversion:
   def unsupported() -> int:
       import os
       return 0
   Check that fold arrows remain usable after the rejection. Close all modules
   and open another file; no missing-active-document traceback should appear.

5. Temporarily introduce a Python syntax error, then correct it. Allow background
   analysis to finish; current function arrows should return. Syntax errors and
   bounded large-file mode legitimately limit folding; a failed conversion alone
   should not remove arrows from otherwise valid functions.

6. Open F1 Help > Desktop workspace and review the close/reopen and folding
   instructions. In 1.2.1, confirm Compile with PCFC11 is still available after
   a successful fresh conversion. No change to your external compiler is needed.

7. Open Compile with PCFC11, then close and reopen it. The top-right X must
   not remain highlighted with the pointer elsewhere. The compiler field
   should receive initial keyboard focus.

8. Use both Browse buttons. Each must use PyCForge custom chrome, directory
   tree, location and filename controls, with no Python preview pane. Select
   pcfc11.exe, then choose an output filename such as program.exe or program.o.
   Confirm names are preserved; Cancel must leave the previous path unchanged.
   Choosing an existing output must ask Confirm Replace in the same dialog.

If anything fails, keep the PowerShell traceback and send the Python files,
installed version, exact steps, whether Generated C/split view were visible,
and any conversion diagnostic. Do not discard unsaved code to reproduce it.
