feat: add wrap_size option to app rules for natural window sizing in tiles

[qeude]

Problem

There is a convenient option to force tiling for some apps using app_rules:

{ app_id = "com.apple.iphonesimulator", workspace = 0, floating = false }

This prevents the Simulator from floating, but it leads to weird sizing behavior because the layout still stretches the window to fill the allocated column size.

Solution

This PR adds a wrap_size option to app_rules. When wrap_size = true and floating = false, the layout column shrinks to wrap the window's actual natural size instead of stretching it to the default column ratio.

Usage

{ app_id = "com.apple.iphonesimulator", workspace = 0, floating = false, wrap_size = true }

How it works

1. Config: Added wrap_size: bool to AppWorkspaceRule
2. Virtual Workspace Manager: wrap_size is propagated through AppRuleAssignment and stored per-window in window_rule_wrap_size
3. Layout Engine: During WindowsOnScreenUpdated, windows with wrap_size get WindowLayoutConstraints with wrap_size: true and is_resizable: false, using their current natural size as locked dimensions
4. Scrolling Layout: In calculate_layout, if a column contains a wrap_size window, the column width uses the locked width directly instead of the ratio-based width
5. Resize handling: WindowResized updates the locked dimensions so the column tracks the window's new size

Testing

Added unit tests covering:

• Config TOML parsing of wrap_size
• VWM rule assignment producing wrap_size
• wrap_size suppression when floating = true
• Layout engine constraint creation
• Resize-driven constraint updates
• Scrolling layout column width wrapping