Profile PRK.Client options menu UI lag

Capture and analyze a CPU trace from the running PRK.Client while reproducing severe options-menu lag. Identify the dominant UI hot paths and report evidence-backed optimization targets without modifying the client during capture. Acceptance criteria: - A CPU sampling trace covers an interactive options-menu reproduction. - The trace is validated and analyzed with managed symbols where available. - Dominant call stacks and practical next steps are documented for implementation. Findings: - The worst five-second interval spent about 85% of main-thread wall time in UI painting; options-model update and layout costs were negligible. - SKCanvas.DrawImage consumed about 24.8 seconds across the 75-second capture. Roughly 58.5% of that image time came from DrawWindow -> DrawNineSlice, and 25.5% from DrawWindow -> EndLayer composition. - The 800x580 window chrome paints two translucent offscreen layers (outer and inner) and composites them back for damaged regions. This is the primary optimization target. - Recommended next step: benchmark cached/precomposed window chrome or a single composition layer, while retaining damage clipping, then compare another identical trace.