Lay out the overlay panels in a fixed 3-column scheme

Panels used to Begin at cascade positions, so they overlapped and clipped. A new
apply_panel_layout() in app_chrome positions/sizes each panel from the main
viewport work area (ImGuiCond_FirstUseEver, still movable): Injection left column
full height (room for hook diagnostics), Controllers/Video/Audio stacked in the
center column, Log right edge full height (max room for the log stream). Added a
"View -> Reset layout" menu item (request_layout_reset / apply_layout_end_frame
re-apply the defaults once via ImGuiCond_Always). Each panel now calls
apply_panel_layout(Panel::X) instead of its own ad-hoc SetNextWindowPos/Size.

Verified live: captured the host overlay -- Injection (left, full height),
Controllers/Video/Audio (center stack), Log (right, full height), no overlap among
the panels. x64 build + ctest green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

README.md

@@ -75,17 +75,6 @@ is removed from this list once done — so the top item is always next. The
 self-verifiable tooling / UI / input items come first; the game-pipeline items that
 need a real game (and Remote Play) to fully validate come last.
 
-- **Auto-size and lay out the overlay windows so none need manual resizing.** Panels
-  currently `Begin` at default cascade positions, so they overlap and clip. Give each
-  `ImGuiWindowFlags_AlwaysAutoResize` and an initial position computed from
-  `ImGui::GetMainViewport()->WorkPos/WorkSize`, applied with `ImGuiCond_FirstUseEver`
-  (still movable), plus a **View → Reset layout** menu item that re-applies it. Target
-  layout: **Injection** left/top (room to grow downward for hook diagnostics);
-  **Controllers** top-center; **Video mirror** center, below Controllers; **Audio
-  mirror** below Video; **Log** right edge, full height (most room for the log
-  stream). Auto-resize fits these because they're all control/debug panels — the live
-  mirror image is drawn to the whole host window *behind* the overlay, not inside a
-  panel.
 - **Fix the Audio panel "live" column.** It overlays a green dot and grey "idle"
   because liveness is recomputed each frame from the per-stream `frames_rendered`
   delta, which is zero on most frames (buffers release in bursts), so it flickers.