perf: HUDTextCache — reuse text SDL textures, skip when HUD hidden

tests/test_video_playback_device.py

@@ -775,6 +775,7 @@ else:
         import sdl2.sdlttf as _ttf9
 
         from r36s_dlna_browser.ui import screens as _screens9, theme as _theme9
+        _cache9 = _screens9.HUDTextCache()
 
         # ── SDL + TTF init (no vsync so phases are timed cleanly) ────────────
         sdl2.SDL_SetHint(b"SDL_VIDEODRIVER", b"kmsdrm,offscreen")
@@ -906,9 +907,9 @@ else:
             sdl2.SDL_RenderCopy(_ren9, _tex9, None, _dst9)
             _t_video = (time.monotonic() - _t0) * 1e6
 
-            # Phase 3 — draw_playback() — all TTF_RenderUTF8_Blended + fill-rects.
+            # Phase 3 — draw_playback() with texture cache (warm after first frame).
             _t0 = time.monotonic()
-            _screens9.draw_playback(_ren9, _font9, _state9, _layout9, _icons9 or None)
+            _screens9.draw_playback(_ren9, _font9, _state9, _layout9, _icons9 or None, cache=_cache9)
             _t_hud = (time.monotonic() - _t0) * 1e6
 
             # Phase 4 — Present (no vsync → should be near-zero on HW renderer).
@@ -928,6 +929,7 @@ else:
             pass
 
         # Cleanup.
+        _cache9.invalidate()
         for _itex_v in _icons9.values():
             sdl2.SDL_DestroyTexture(_itex_v)
         if _tex9:
@@ -955,9 +957,9 @@ else:
         print("  --- Section 9 HUD Timing Report ---")
         print(f"  Frames measured (excl warmup)    : {len(_hud9)}")
         _stat9("SDL_UpdateNVTexture (synthetic NV12)", _upload9)
-        _stat9("SDL_RenderClear+RenderCopy (video)",   _video9)
-        _stat9("draw_playback() — TTF+fills+icons",    _hud9)
-        _stat9("SDL_RenderPresent (no vsync)",          _pres9)
+        _stat9("SDL_RenderClear+RenderCopy (video)",      _video9)
+        _stat9("draw_playback() — cached TTF+fills+icons", _hud9)
+        _stat9("SDL_RenderPresent (no vsync)",             _pres9)
 
         _hud_mean   = statistics.mean(_hud9)   if _hud9   else 0
         _total9_mean = (statistics.mean(_upload9) + statistics.mean(_video9) +