Parse CSI insert mode

Author: SqlRush

docs/cc-100-roadmap.md

@@ -148,6 +148,8 @@ M7 补充：terminal sequence dispatcher 现在把 SS3 application cursor (`ESC
 
 M7 补充：terminal CSI parser 现在把 DEC `?1h/l` application cursor mode 解析成独立 mode action，和 SS3 application cursor key 解析闭环。
 
+M7 补充：terminal CSI parser 现在把普通 `CSI 4h/l` insert/replace mode 解析成 `insertMode` action，避免 ECMA mode set/reset 序列落入 unknown。
+
 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

@@ -255,6 +255,7 @@ test/parity/                 # golden tests against TS/official behavior
 - 本轮补充：terminal ESC parser 把 HTS horizontal-tab-set (`ESC H`) 归入 cursor/tab-set action，和 CSI tab-clear 控制序列形成闭环。
 - 本轮补充：terminal sequence dispatcher 把 SS3 application cursor (`ESC OA`/`OB`/`OC`/`OD`) 归入结构化 cursor move action，避免 application cursor mode 序列落入 unknown。
 - 本轮补充：terminal CSI parser 把 DEC `?1h/l` application cursor mode 解析成独立 mode action，和 SS3 application cursor key 解析闭环。
+- 本轮补充：terminal CSI parser 把普通 `CSI 4h/l` insert/replace mode 解析成 `insertMode` action，避免 ECMA mode set/reset 序列落入 unknown。
 - 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

@@ -208,6 +208,7 @@ M7 progress now includes:
 - `internal/tui`: terminal CSI parser now recognizes DEC highlight, UTF-8, and urxvt numeric mouse modes (`?1001h/l`, `?1005h/l`, `?1015h/l`) as mouse-tracking mode actions.
 - `internal/tui`: terminal CSI parser now recognizes xterm alternate scroll mode (`?1007h/l`) as a structured mode action instead of an unknown sequence.
 - `internal/tui`: terminal CSI parser now recognizes DEC application cursor mode (`?1h/l`) as a structured mode action, pairing with SS3 application cursor key parsing.
+- `internal/tui`: terminal CSI parser now recognizes ordinary ECMA insert/replace mode (`CSI 4h/l`) as a structured `insertMode` action.
 - `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`: terminal key parsing now accepts CSI-u/kitty keyboard protocol sequences for existing ctrl/alt editing keys, shift-enter, shift-tab, and printable shift-only runes.

internal/tui/terminal_csi.go

@@ -63,6 +63,8 @@ const (
 	CSICommandRestoreCursor    byte = 'u'
 	CSICommandTerminalParams   byte = 'x'
 
+	CSIModeInsert = 4
+
 	DECModeApplicationCursor  = 1
 	DECModeCursorVisible      = 25
 	DECModeAltScreen          = 47
@@ -219,6 +221,7 @@ const (
 	CSIModeActionApplicationCursor CSIModeActionType = "applicationCursor"
 	CSIModeActionAlternateScreen   CSIModeActionType = "alternateScreen"
 	CSIModeActionBracketedPaste    CSIModeActionType = "bracketedPaste"
+	CSIModeActionInsert            CSIModeActionType = "insertMode"
 	CSIModeActionMouseTracking     CSIModeActionType = "mouseTracking"
 	CSIModeActionFocusEvents       CSIModeActionType = "focusEvents"
 	CSIModeActionAlternateScroll   CSIModeActionType = "alternateScroll"
@@ -402,6 +405,11 @@ func ParseCSISequence(sequence string) (CSIAction, bool) {
 			return action, true
 		}
 	}
+	if privateMode == 0 && (final == CSICommandSetMode || final == CSICommandResetMode) {
+		if action, ok := csiModeAction(p0, final == CSICommandSetMode); ok {
+			return action, true
+		}
+	}
 
 	return CSIAction{Type: CSIActionUnknown, Sequence: sequence}, true
 }
@@ -588,6 +596,15 @@ func csiPrivateModeAction(mode int, enabled bool) (CSIAction, bool) {
 	}
 }
 
+func csiModeAction(mode int, enabled bool) (CSIAction, bool) {
+	switch mode {
+	case CSIModeInsert:
+		return CSIAction{Type: CSIActionMode, Mode: CSIModeAction{Type: CSIModeActionInsert, Enabled: enabled}}, true
+	default:
+		return CSIAction{}, false
+	}
+}
+
 func csiMouseModeAction(mode CSIMouseTrackingMode, enabled bool) CSIAction {
 	if !enabled {
 		mode = CSIMouseTrackingOff

internal/tui/tui_test.go

@@ -3642,6 +3642,8 @@ func TestParseCSISequenceActions(t *testing.T) {
 		seq  string
 		want CSIModeAction
 	}{
+		{seq: "\x1b[4h", want: CSIModeAction{Type: CSIModeActionInsert, Enabled: true}},
+		{seq: "\x1b[4l", want: CSIModeAction{Type: CSIModeActionInsert, Enabled: false}},
 		{seq: "\x1b[?1h", want: CSIModeAction{Type: CSIModeActionApplicationCursor, Enabled: true}},
 		{seq: "\x1b[?1l", want: CSIModeAction{Type: CSIModeActionApplicationCursor, Enabled: false}},
 		{seq: EnterAlternateScreen, want: CSIModeAction{Type: CSIModeActionAlternateScreen, Enabled: true}},