Add game-frame-synced flip toggle + multi-series colored perf graphs

Frame sync: new "Sync flip to game frames" toggle in the Video mirror panel
(Hooked source only -- WGC frames are delivered by the compositor at monitor
refresh and don't carry the game's true present cadence, so it's disabled there).
When on, the main loop waits for the hook's next published frame (its generation
bump) before rendering and presents with sync interval 0, so the tool flips in
lockstep with the game instead of vsync. The wait pumps messages to stay
responsive and times out after 200 ms so a paused/stalled game can't hang the
overlay. timeBeginPeriod(1) keeps the wait's Sleep(1) granular; links winmm.
render_frame() gained a sync_interval parameter (default 1 = vsync).

Perf graphs: the old graphs drew the tool's frametime and FPS as single same-color
lines. Replaced with a custom multi-series plotter (ImDrawList polylines) that
overlays Tool (blue), Game present (green), and Hook publish (orange) -- or Tool +
WGC capture in WGC mode -- in distinct colors with a colored legend, for both an
FPS (0-144) and a frametime (0-33 ms) view. Game/hook rates come from an EdgeRate
tracker that measures the instantaneous rate the moment each counter advances, so
the lines have real per-frame resolution rather than 0.5 s stair-steps.

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

host/CMakeLists.txt

@@ -36,6 +36,7 @@ target_link_libraries(coop_host PRIVATE
 	windowsapp
 	xinput
 	mmdevapi
+	winmm
 	ole32)
 
 set_target_properties(coop_host PROPERTIES OUTPUT_NAME "coop_host")