options: make sub-ass-override default to 'scale'

Previous commit changed the semantics of 'yes', so change the default to
scale to prevent unexpected user facing changes

DOCS/interface-changes/sub-ass-override-default.txt

@@ -1 +1,2 @@
 move 'scale' above 'force' for `sub-ass-override` in documentation as well as code. This more accurately reflects destructiveness of these options.
+change `sub-ass-override` default from 'yes' to 'scale'. This should result in no effective changes because 'yes' used to unintentionally do what 'scale' should've done.

DOCS/man/options.rst

@@ -2510,8 +2510,8 @@ Subtitles
             overrides.
     :yes:   Apply all the ``--sub-ass-*`` style override options. Changing the
             default for any of these options can lead to incorrect subtitle
-            rendering (default).
-    :scale: Like ``yes``, but also apply ``--sub-scale``.
+            rendering.
+    :scale: Like ``yes``, but also apply ``--sub-scale`` (default).
     :force: Like ``yes``, but also force all ``--sub-*`` options. Can break
             rendering easily.
     :strip: Radically strip all ASS tags and styles from the subtitle. This

options/options.c

@@ -383,7 +383,7 @@ const struct m_sub_options mp_subtitle_shared_sub_opts = {
         .sub_visibility[0] = true,
         .sub_visibility[1] = true,
         .sub_pos[0] = 100,
-        .ass_style_override[0] = ASS_STYLE_OVERRIDE_YES,
+        .ass_style_override[0] = ASS_STYLE_OVERRIDE_SCALE,
         .ass_style_override[1] = ASS_STYLE_OVERRIDE_STRIP,
     },
     .change_flags = UPDATE_OSD,