real chrome UI -> dev websocket server -> codex app-server turn/start
main: 60aec28a9c6fdb7417a7382ec094ccc4984d0738
pr: 6e039074702caad3af6c96676a1c491b05bea35b
source: decoded outgoing provider protocol logs; JSON strings expose whitespace

main model=gpt-6.1-sol
["  @@ -5,1 +5,1 @@"]
["  @@ -0,0 +3,1 @@","  +  return `Hi, ${name}!`;"]
["  @@ -0,0 +6,1 @@","  +export const version = 2;"]

pr model=gpt-6.1-sol
["  @@ -5,1 +5,1 @@","   "]
["  @@ -0,0 +3,1 @@","  +  return `Hi, ${name}!`;\t"]
["  @@ -0,0 +6,1 @@","  +export const version = 2;"]

pr split-view multiline model=gpt-6.1-sol
["  @@ -4,2 +3,3 @@","  +  return `Hi, ${name}!`;\t","   }","   "]

PASS: main loses blank context row and terminal tab; PR preserves both.
PASS: ordinary version-line excerpt unchanged.
PASS: split-view multiline range retains tab, closing brace, and final blank row.
Observed completed real Codex responses also report blank row and tab absent on main, present on PR.