[#109.3] Define and document precedence rules for component sizing systems

[thomasnemer]

Parent Issue

Part of #109 - Window resize behavior conflicts with component sizing

Problem

The new resize system interacts with multiple existing sizing mechanisms without clear precedence rules:

• FlexLayout's grow and shrink factors
• Component's withSize() initial dimensions
• Layout manager's setBounds() calls
• Parent/child resize propagation
• AxisResizeBehavior settings

These systems were not designed to work together and have unclear precedence rules, leading to conflicts.

Tasks

1. Document the intended precedence in CLAUDE.md:

   • When does FlexLayout override component size?
   • When does AxisResizeBehavior take precedence?
   • How do grow/shrink factors interact with FIXED behavior?
   • What happens when layout says one size but resize behavior says another?

2. Implement the precedence rules consistently:

   • Modify Component::setBounds() to respect precedence
   • Modify FlexLayout::layout() to respect precedence
   • Ensure onParentResize() follows the rules

3. Add tests that validate precedence:

   • FlexLayout with FIXED components
   • FlexLayout with FILL components and grow factors
   • Conflicting size specifications

Possible Approaches

1. Layout managers always win: setBounds() from layout overrides everything, resize behavior only applies to parent window resizes
2. Resize behavior as constraints: Layout managers work within constraints set by resize behavior
3. Two-pass system: Calculate layout first, then apply resize behaviors as modifications
4. Explicit priority flags: Add priority parameter to resolve conflicts

Success Criteria

• Precedence rules clearly documented in CLAUDE.md
• Implementation consistently follows documented rules
• No conflicts between FlexLayout and AxisResizeBehavior
• Unit tests cover precedence edge cases
• Demo app behavior matches documented expectations

Related Code

• include/bombfork/prong/core/component.h
• include/bombfork/prong/layout/flex_layout.h
• CLAUDE.md - Resize Behavior section

Dependencies

Should be worked on after #109.1 and #109.2 are resolved, as it builds on understanding gained from fixing those issues.