refactor(mpv): move ModernZ overrides into mpv.conf via script-opts-append

- drop defaults/etc/mpv/script-opts/modernz.conf (deploy timing conflict
  with mpv-modernz-git)
- put all ModernZ tweaks in mpv.conf: Catppuccin Lavender accent, scale
  0.75, title font 18, ontop_button off, autofit-larger 80%
- quote hex values to survive mpv's mid-line # comment parsing
- niri window-rule opens mpv floating
- doctor no longer compares mpv configs (now directly owned by pkg)

defaults/etc/mpv/mpv.conf

@@ -3,3 +3,21 @@ osc=no
 
 # Hide native title bar for a cleaner borderless look (ModernZ draws its own).
 title-bar=no
+
+# Cap window size at 80% of screen for oversized videos.
+autofit-larger=80%x80%
+
+# --- ModernZ overrides ---
+# mpv treats # as a mid-line comment; the full value must be quoted so the
+# hex color survives.
+script-opts-append="modernz-seekbarfg_color=#b4befe"
+script-opts-append="modernz-seek_handle_color=#b4befe"
+script-opts-append="modernz-seek_handle_border_color=#b4befe"
+script-opts-append="modernz-hover_effect_color=#b4befe"
+script-opts-append="modernz-nibble_color=#b4befe"
+script-opts-append="modernz-ontop_button=no"
+script-opts-append="modernz-window_title_font_size=18"
+
+# Scale OSC down globally
+script-opts-append="modernz-scalewindowed=0.75"
+script-opts-append="modernz-scalefullscreen=0.75"