Move now-playing blink/autoplay out of the interrupt too

show_now_play_link (blinking highlight for the currently playing track
in the list, plus the end-of-track autoplay/parse_url check) still ran
inside int_text_off via pt_play, doing its own extra page switch
(set_Textpage_lite) and an 80-byte write - on top of the analyzer this
was the remaining source of the vertical stripe flicker, specifically
when the playing track is scrolled into view. Split it out of pt_play
and call it from the main loop alongside the analyzer; the player tick
itself is untouched.

Confirmed on hardware: no flicker left, including across autoplay to
the next track.

zifi.asm

@@ -106,13 +106,14 @@ do_after_load	ld a,0
 
 main_ex		call wait_frame
 
-		ld a,(music_sw+1)	; draw the volume-bar analyzer here in the foreground,
+		ld a,(music_sw+1)	; music-playing UI bits (now-playing blink, volume-bar
-		or a			; frame-synced but off the raster-critical interrupt chain
+		or a			; analyzer) done here in the foreground, frame-synced,
-		jr z,skip_analizator
+		jr z,skip_music_ui	; instead of inside the raster-critical interrupt chain
+		call show_now_play_link
 		ld a,(save_mode+1)
 		or a
 		call nz,music_analizator
-skip_analizator
+skip_music_ui
 
 do_start_music	ld a,1
 		or a
@@ -2273,8 +2274,8 @@ int_ex3		ld hl,0
 
 pt_play		call set_music_pages_lite
 		call music_player_play
-		call restore_music_pages_lite	; PAGE3 only needed for the tick itself -
+		jp restore_music_pages_lite	; the link-blink/autoplay tail (show_now_play_link)
-					; restore it before the (page-independent) link-blink/autoplay tail below
+					; is now called separately from the main loop, not from here
 
 show_now_play_link	ld a,0
 		or a