Parse CSI horizontal margin sequences

Author: SqlRush

docs/cc-100-roadmap.md

@@ -222,6 +222,8 @@ M7 补充：terminal CSI parser 现在把 DEC `?67h/l` backarrow key mode 解析
 
 M7 补充：terminal CSI parser 现在把 DEC `?69h/l` left/right margin mode 解析成结构化 `leftRightMarginMode` mode action，补齐 scroll-region 相邻的 margin 状态序列。
 
+M7 补充：terminal CSI parser 现在把带参数的 `CSI Pl;Pr s` 解析成 left/right horizontal margin region action，同时保留无参数 `CSI s` save-cursor 语义，和 DEC `?69h/l` margin mode 闭环。
+
 M7 补充：terminal CSI parser 现在把 REP repeat-preceding-character (`CSI b`/`CSI 4b`) 解析成 edit action，visible-text/snapshot pipeline 和 ANSI message wrapping/trim 会按重复次数展开前一个可重复 grapheme。
 
 M7 补充：terminal CSI parser 现在按 ANSI 默认参数解析 scroll-region (`CSI r`/`CSI ;10r`)，缺失 top 默认为 1，缺失 bottom 保持为 0 表示 reset/full-height，避免把 reset 误判为单行区域。

docs/claude-code-go-rewrite-plan.md

@@ -290,6 +290,7 @@ test/parity/                 # golden tests against TS/official behavior
 - 本轮补充：terminal CSI parser 把 DEC `?66h/l` application keypad mode 解析成结构化 `applicationKeypad` mode action，补齐 application cursor mode 相邻的输入状态序列。
 - 本轮补充：terminal CSI parser 把 DEC `?67h/l` backarrow key mode 解析成结构化 `backarrowKey` mode action，补齐键盘输入状态序列。
 - 本轮补充：terminal CSI parser 把 DEC `?69h/l` left/right margin mode 解析成结构化 `leftRightMarginMode` mode action，补齐 scroll-region 相邻的 margin 状态序列。
+- 本轮补充：terminal CSI parser 现在把带参数的 `CSI Pl;Pr s` 解析成 left/right horizontal margin region action，同时保留无参数 `CSI s` save-cursor 语义，和 DEC `?69h/l` margin mode 闭环。
 - 本轮补充：terminal CSI parser 把 REP repeat-preceding-character (`CSI b`) 归入 edit action，visible-text/snapshot pipeline 和 ANSI message wrapping/trim 会按重复次数展开前一个可重复 grapheme。
 - 本轮补充：terminal CSI parser 按 ANSI 默认参数解析 scroll-region (`CSI r`/`CSI ;10r`)，缺失 top 默认为 1，缺失 bottom 保持 0 表示 reset/full-height，避免 reset scroll region 被误判为单行区域。
 - 本轮补充：terminal CSI parser 把 DECSTR soft reset (`CSI !p`) 归入 reset action，并在 terminal parser 中清理 SGR/link 状态。

docs/first-second-parity-audit.md

@@ -244,6 +244,7 @@ M7 progress now includes:
 - `internal/tui`: terminal CSI parser now recognizes DEC application keypad mode (`?66h/l`) as a structured `applicationKeypad` mode action.
 - `internal/tui`: terminal CSI parser now recognizes DEC backarrow key mode (`?67h/l`) as a structured `backarrowKey` mode action.
 - `internal/tui`: terminal CSI parser now recognizes DEC left/right margin mode (`?69h/l`) as a structured `leftRightMarginMode` action.
+- `internal/tui`: terminal CSI parsing now distinguishes parameterized `CSI Pl;Pr s` left/right horizontal margin regions from bare `CSI s` save-cursor semantics.
 - `internal/tui`: keybinding config, keymap resolution, and interaction script named-key input now accept terminal aliases for `ctrl-h`/`ctrl-i`/`ctrl-j`/`ctrl-m`, `ctrl-[`, and `ctrl-?`, including `control-*` and compact/camel variants.
 - `internal/tui`: keybinding config now accepts page navigation aliases such as `pgup`, `pg-up`, `prior`, `pgdn`, `pg-down`, and `next`.
 - `internal/tui`: keybinding config and named-key script input now accept DOM-style arrow key aliases such as `arrowLeft`, `arrowRight`, `arrowUp`, `arrowDown`, and modifier-arrow variants.

internal/tui/terminal_csi.go

@@ -220,16 +220,19 @@ type CSIReportAction struct {
 type CSIScrollActionType string
 
 const (
-	CSIScrollActionUp        CSIScrollActionType = "up"
-	CSIScrollActionDown      CSIScrollActionType = "down"
-	CSIScrollActionSetRegion CSIScrollActionType = "setRegion"
+	CSIScrollActionUp                  CSIScrollActionType = "up"
+	CSIScrollActionDown                CSIScrollActionType = "down"
+	CSIScrollActionSetRegion           CSIScrollActionType = "setRegion"
+	CSIScrollActionSetHorizontalRegion CSIScrollActionType = "setHorizontalRegion"
 )
 
 type CSIScrollAction struct {
 	Type   CSIScrollActionType
 	Count  int
 	Top    int
 	Bottom int
+	Left   int
+	Right  int
 }
 
 type CSIModeActionType string
@@ -423,6 +426,9 @@ func ParseCSISequence(sequence string) (CSIAction, bool) {
 	case CSICommandScrollRegion:
 		return csiScrollRegion(params), true
 	case CSICommandSaveCursor:
+		if privateMode == 0 && len(params) > 0 {
+			return csiHorizontalRegion(params), true
+		}
 		return CSIAction{Type: CSIActionCursor, Cursor: CSICursorAction{Type: CSICursorActionSave}}, true
 	case CSICommandWindowReport:
 		return csiWindowReport(csiParamDefault(params, 0, 0), privateMode), true
@@ -549,6 +555,18 @@ func csiScrollRegion(params []int) CSIAction {
 	return CSIAction{Type: CSIActionScroll, Scroll: CSIScrollAction{Type: CSIScrollActionSetRegion, Top: top, Bottom: bottom}}
 }
 
+func csiHorizontalRegion(params []int) CSIAction {
+	left := 1
+	if len(params) > 0 && params[0] > 0 {
+		left = params[0]
+	}
+	right := 0
+	if len(params) > 1 && params[1] > 0 {
+		right = params[1]
+	}
+	return CSIAction{Type: CSIActionScroll, Scroll: CSIScrollAction{Type: CSIScrollActionSetHorizontalRegion, Left: left, Right: right}}
+}
+
 func csiModeListAction(params []int, private bool, enabled bool) (CSIAction, bool) {
 	if len(params) <= 1 {
 		return CSIAction{}, false

internal/tui/tui_test.go

@@ -3817,6 +3817,8 @@ func TestParseCSISequenceActions(t *testing.T) {
 		{seq: CSISequence(4, 10, "r"), want: CSIScrollAction{Type: CSIScrollActionSetRegion, Top: 4, Bottom: 10}},
 		{seq: ResetScrollRegion, want: CSIScrollAction{Type: CSIScrollActionSetRegion, Top: 1}},
 		{seq: CSISequence(";10r"), want: CSIScrollAction{Type: CSIScrollActionSetRegion, Top: 1, Bottom: 10}},
+		{seq: CSISequence(10, 80, "s"), want: CSIScrollAction{Type: CSIScrollActionSetHorizontalRegion, Left: 10, Right: 80}},
+		{seq: CSISequence(";120s"), want: CSIScrollAction{Type: CSIScrollActionSetHorizontalRegion, Left: 1, Right: 120}},
 	}
 	for _, tc := range scrollCases {
 		action, ok := ParseCSISequence(tc.seq)
@@ -3918,6 +3920,11 @@ func TestParseCSISequenceActions(t *testing.T) {
 	if len(actions) != 1 || actions[0].Type != TerminalActionMode || len(actions[0].Modes) != 3 || actions[0].Mode != actions[0].Modes[0] {
 		t.Fatalf("terminal parser multi mode actions = %#v", actions)
 	}
+
+	actions = parser.Feed(CSISequence(5, 40, "s"))
+	if len(actions) != 1 || actions[0].Type != TerminalActionScroll || actions[0].Scroll.Type != CSIScrollActionSetHorizontalRegion || actions[0].Scroll.Left != 5 || actions[0].Scroll.Right != 40 {
+		t.Fatalf("terminal parser horizontal region actions = %#v", actions)
+	}
 }
 
 func TestParseESCSequenceActions(t *testing.T) {