Fix diff buffer window management to preserve layout

[stevemolitor]

Summary

This PR addresses issue #24 where diff buffers were disrupting the window layout by replacing existing windows instead of creating new ones.

Changes

• Added inhibit-same-window parameter to both default and tab-specific display configurations
• Removed display-buffer-pop-up-frame to prevent disorienting frame creation
• Modified display-buffer actions in monet.el:1328 and monet.el:1344

Expected Behavior

• Diff buffers now create new windows instead of reusing existing ones
• Original window layout is preserved during diff operations
• No new frames are created (stays within current frame)
• Window layout remains intact after diff resolution

Testing

• Test with multiple edit cycles to ensure window layout stability
• Verify diff buffers appear in new windows
• Confirm original buffers return after diff resolution

Fixes #24