Remove references to "v4" throughout the code and documentation

tests/artifacts/transcriptions/Rod_Moser_Letter_-_p1.jpg.txt

@@ -3,13 +3,13 @@ provider: openrouter
 model: openai/gpt-5.3-codex
 ---
 [document body mixed]
-JOHN ISBILL                                                                 R. T. MOSER
+JOHN ISBILL                                              R. T. MOSER
 
 ISBILL & MOSER
 DEALERS IN
 GENERAL MERCHANDISE
 
-Vonore, Tenn., [handwritten: July 27-] 191[handwritten: 3]
+Vonore, Tenn., [handwritten: May 27-] 191[handwritten: 3]
 
 [handwritten: Dear Uncle Aunt & Cousins
 I was at home a
@@ -17,17 +17,16 @@ few nights ago & saw a
 letter from your folks, so
 I decided to write you
 a few lines myself as
-I am contemplat[ing?] a
+I am contemplating a
 trip out west next summer
-& want [lots?] to go
-where I am [stopen?].
-
+& want lots of places to go
+where I am [there?].
 Am getting
-up in years & [unmarried?].
-so you see the object of
+up in years & [remembering?]
+so your one the object of
 my trip, is to get a wife
 If there is any old maids
-or widows out there, I
-want you to [hire?] them
-at [par?] and [marry?] me [to?] them
+or widows out there I
+want you to hire them
+at [our?] [land?] [my?] at [them?]
 as soon as I get there.]