Keep ResizableLib out-of-tree instead of inlining it

Summary

The proposed ResizableLib inlining is declined.

Current main keeps ResizableLib in its current external/submodule-owned shape instead of copying it into srchybrid/.

Why This Is Wont-Fix

• Inlining a stable legacy UI helper creates ownership churn with little runtime value.
• REF-032 is the more meaningful long-term direction for these dialog/layout surfaces; inlining first would add churn on code that may later be replaced.
• The branch direction favors avoiding dependency-topology churn unless it buys concrete stability or compatibility gains.

Disposition

• Marked Wont-Fix
• Keep the current ResizableLib ownership model
• Revisit only if workspace materialization or future MFC-host work makes that topology untenable