Change animation frames (#3627)

## Description
- Changes animation frames to be smaller
- Cleans up file names and popup logic

## tests
- Passes local CI

codex-rs/tui/frames/slug/frame_6.txt

@@ -0,0 +1,17 @@
+                                      
+             d-occtoottdd             
+          tdc5peoptettcdtptd          
+        ttteeepg   egx-optp5od        
+       5tepepdot        oteeeet       
+      poeeepootpo         -ooeot      
+     c-5e5edtceodet        -oo5e      
+     d txe   gdoe5do        dtede     
+     x exe   deox5ee        xtoee     
+     d-e-e  5peepc5tdxtxddttd-o5e     
+     eeot5dddct e5opteetcoooeteog     
+      5 e 5xeec5g  gpgggppgeoo5e      
+       t c 5te           tcd55ee      
+        -eodppt       dtdd5ptt        
+         egxptgtgcxddttppgccp         
+            d-cpttdddedttp            
+