Parse terminal ESC charset selections

Author: SqlRush

docs/cc-100-roadmap.md

@@ -316,6 +316,8 @@ M7 补充：terminal CSI parser 现在把带参数的 `CSI Pl;Pr s` 解析成 le
 
 M7 补充：terminal CSI parser 现在识别带 intermediate space 的 `CSI Ps SP @` / `CSI Ps SP A` scroll-left/right 序列，避免误解析成 insert-characters 或 cursor-up。
 
+M7 补充：terminal ESC parser 现在把 charset selection (`ESC ( B` / `ESC ) 0`) 解析成结构化 charset action，并在 terminal parser 可见文本管线中消费，避免常见终端 charset 选择序列残留为 unknown。
+
 M7 补充：terminal CSI parser 现在把 DEC selective erase `CSI ? Ps J` / `CSI ? Ps K` 标记为 selective display/line erase，和普通 ED/EL 区分开。
 
 M7 补充：terminal CSI parser 现在把 ECMA `CSI Ps N` / `CSI Ps O` 解析成 erase-in-field / erase-in-area action，覆盖 to-end/to-start/all 三种 region。
@@ -948,7 +950,7 @@ M7 补充：prompt history `LogEntry` 读取现在接受 `sessionID`/`session`/`
 
 本轮补充：terminal CSI parser 现在把 DEC `?2026h/l` synchronized output mode 解析成 mode action，和 renderer/snapshot 的 BSU/ESU 包裹路径闭环。
 
-本轮补充：terminal ESC helper 增加官方 ESC final-byte 判定和 `ParseESCSequence`/`ParseESCContent`，覆盖 RIS reset、DECSC/DECRC save/restore、IND/RI/NEL cursor action、HTS/charset ignored 分支和 unknown sequence fallback。
+本轮补充：terminal ESC helper 增加官方 ESC final-byte 判定和 `ParseESCSequence`/`ParseESCContent`，覆盖 RIS reset、DECSC/DECRC save/restore、IND/RI/NEL cursor action、HTS、charset selection 和 unknown sequence fallback。
 
 本轮补充：terminal SGR helper 增加官方 `TextStyle` 状态解析基础，覆盖 reset、bold/dim/italic/underline/blink/inverse/hidden/strikethrough/overline、普通/亮色命名色、256 色、RGB 色、underline color、分号和冒号参数格式；完整 ANSI parser/render style parity 仍继续推进。
 

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

@@ -453,6 +453,7 @@ test/parity/                 # golden tests against TS/official behavior
 - 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 现在识别带 intermediate space 的 `CSI Ps SP @` / `CSI Ps SP A` scroll-left/right 序列，避免误解析成 insert-characters 或 cursor-up。
+- 本轮补充：terminal ESC parser 现在把 charset selection (`ESC ( B` / `ESC ) 0`) 解析成结构化 charset action，并在 terminal parser 可见文本管线中消费，避免常见终端 charset 选择序列残留为 unknown。
 - 本轮补充：terminal CSI parser 现在把 DEC selective erase `CSI ? Ps J` / `CSI ? Ps K` 标记为 selective display/line erase，和普通 ED/EL 区分开。
 - 本轮补充：terminal CSI parser 现在把 ECMA `CSI Ps N` / `CSI Ps O` 解析成 erase-in-field / erase-in-area action，覆盖 to-end/to-start/all 三种 region。
 - 本轮补充：terminal CSI parser 把 DEC insert/delete columns (`CSI Ps ' }` / `CSI Ps ' ~`) 归入 edit action，避免列编辑控制序列落入 unknown fallback。
@@ -547,7 +548,7 @@ test/parity/                 # golden tests against TS/official behavior
 - 本轮补充：terminal CSI parser 现在也把 DEC `?1001h/l` highlight、`?1005h/l` UTF-8 mouse mode、`?1015h/l` urxvt numeric mouse mode 和 xterm `?1016h/l` SGR-pixels mouse mode 解析成 mouseTracking action，和输入侧 numeric/SGR mouse 兼容面闭环。
 - 本轮补充：terminal CSI parser 现在把 xterm `?1007h/l` alternate scroll mode 解析成独立 mode action，避免 alternate-screen wheel 兼容序列落入 unknown。
 - 本轮补充：terminal CSI parser 现在把 DEC `?2026h/l` synchronized output mode 解析成 mode action，和 renderer/snapshot 的 BSU/ESU 包裹路径闭环。
-- 本轮补充：terminal ESC helper 增加官方 ESC final-byte 判定和 `ParseESCSequence`/`ParseESCContent`，覆盖 RIS reset、DECSC/DECRC save/restore、IND/RI/NEL cursor action、HTS/charset ignored 分支和 unknown sequence fallback。
+- 本轮补充：terminal ESC helper 增加官方 ESC final-byte 判定和 `ParseESCSequence`/`ParseESCContent`，覆盖 RIS reset、DECSC/DECRC save/restore、IND/RI/NEL cursor action、HTS、charset selection 和 unknown sequence fallback。
 - 本轮补充：terminal SGR helper 增加官方 `TextStyle` 状态解析基础，覆盖 reset、bold/dim/italic/underline/blink/inverse/hidden/strikethrough/overline、普通/亮色命名色、256 色、RGB 色、underline color、分号和冒号参数格式；完整 ANSI parser/render style 应用仍继续推进。
 - 本轮补充：terminal sequence dispatcher 增加官方 `identifySequence` 等价分流，按 CSI/OSC/ESC/SS3/unknown 识别并委派现有 parser，SS3 按官方 output parser 作为 unknown action；streaming tokenizer 和 text grapheme action 仍继续推进。
 - 本轮补充：terminal tokenizer 增加官方 streaming escape boundary 状态机，支持跨 chunk buffer/flush/reset、CSI/SS3/OSC/DCS/APC 序列边界、OSC BEL/ST terminator、ESC intermediate charset 序列、invalid CSI text fallback 和 opt-in X10 mouse payload 消费；完整 text grapheme action parser 仍继续推进。

docs/first-second-parity-audit.md

@@ -507,6 +507,7 @@ M7 progress now includes:
 - `internal/tui`: key parsing and configurable keybindings now expose `ctrl+space` from raw NUL and Kitty/CSI-u `0u`, `32;5u`, `64;5u`, and `50;5u` forms, with `ctrl-space`/`ctrl-@`/`ctrl-2` and compact `cSpace`/`c@`/`c2` aliases available for user keymaps and scripts.
 - `internal/tui`: key parsing and configurable keybindings now expose Ctrl-backslash, Ctrl-], Ctrl-^/Ctrl-6, and Ctrl-_/Ctrl-/ from raw terminal control bytes and Kitty/CSI-u forms, with symbol, named, and compact aliases available for user keymaps and scripts.
 - `internal/tui`: key parsing and configurable keybindings now expose F1-F12 from common SS3, legacy Linux-console, tilde CSI, and modified CSI function-key sequences, with `f1`, `function-key-1`, and `fn1` style aliases available for user keymaps and scripts.
+- `internal/tui`: terminal ESC parsing now recognizes charset selection sequences such as `ESC ( B` and `ESC ) 0` as structured charset actions and consumes them in visible-text parsing instead of surfacing them as unknown terminal output.
 - `internal/contracts`/`internal/session`: image content blocks now normalize source aliases such as `mediaType`/`mimeType`/`contentType` and `base64`/`payload`, including top-level image block fields, into canonical `ImageSource` values during transcript resume.
 - `internal/tui`: interaction script single-step JSON now unwraps `step`/`scriptStep`/`interactionStep`/`record`/`entry`/`item`/`event` objects in arrays, JSONL records, and wrapper-object step lists.
 - `internal/tui`: interaction script single-step JSON now also unwraps JSON:API/resource-style `resource`/`node`/`attributes`/`properties`/`attrs` step items, so API fixture arrays and JSONL records can keep step resource envelopes.

internal/tui/terminal_esc.go

@@ -22,13 +22,16 @@ type ESCActionType string
 const (
 	ESCActionCursor  ESCActionType = "cursor"
 	ESCActionReset   ESCActionType = "reset"
+	ESCActionCharset ESCActionType = "charset"
 	ESCActionUnknown ESCActionType = "unknown"
 )
 
 type ESCAction struct {
-	Type     ESCActionType
-	Cursor   CSICursorAction
-	Sequence string
+	Type              ESCActionType
+	Cursor            CSICursorAction
+	CharsetSlot       byte
+	CharsetDesignator byte
+	Sequence          string
 }
 
 func IsESCFinal(b byte) bool {
@@ -63,7 +66,7 @@ func ParseESCContent(chars string) (ESCAction, bool) {
 		return ESCAction{Type: ESCActionCursor, Cursor: CSICursorAction{Type: CSICursorActionTabSet}}, true
 	case ESCCharsetSelectLeft, ESCCharsetSelectRight:
 		if len(chars) >= 2 {
-			return ESCAction{}, false
+			return ESCAction{Type: ESCActionCharset, CharsetSlot: chars[0], CharsetDesignator: chars[1], Sequence: ESCPrefix + chars}, true
 		}
 	}
 	return ESCAction{Type: ESCActionUnknown, Sequence: ESCPrefix + chars}, true

internal/tui/terminal_parser.go

@@ -361,6 +361,8 @@ func (p *TerminalParser) processSequence(sequence string) (TerminalAction, bool)
 		case ESCActionReset:
 			p.Reset()
 			return TerminalAction{Type: TerminalActionReset}, true
+		case ESCActionCharset:
+			return TerminalAction{}, false
 		default:
 			return TerminalAction{Type: TerminalActionUnknown, Sequence: action.ESC.Sequence}, true
 		}

internal/tui/terminal_parser_test.go

@@ -46,8 +46,11 @@ func TestTerminalVisibleTextUsesParserAndPreservesRawBell(t *testing.T) {
 		"d" +
 		"\x1b^pm\x1b\\" +
 		"e" +
+		"\x1b(B" +
 		"\x1bXsos\x07" +
-		"f\x07"
+		"f" +
+		"\x1b)0" +
+		"\x07"
 	if got := TerminalVisibleText(input); got != "aredbcdef\x07" {
 		t.Fatalf("visible = %q", got)
 	}

internal/tui/terminal_sequence_test.go

@@ -75,8 +75,9 @@ func TestParseTerminalSequenceDispatchesActions(t *testing.T) {
 		t.Fatalf("unknown esc dispatch = %#v ok=%v", unknown, ok)
 	}
 
-	if ignored, ok := ParseTerminalSequence("\x1b(B"); ok || ignored.Type != "" {
-		t.Fatalf("ignored esc dispatch = %#v ok=%v", ignored, ok)
+	charset, ok := ParseTerminalSequence("\x1b(B")
+	if !ok || charset.Type != TerminalSequenceESC || charset.ESC.Type != ESCActionCharset || charset.ESC.CharsetSlot != '(' || charset.ESC.CharsetDesignator != 'B' {
+		t.Fatalf("charset esc dispatch = %#v ok=%v", charset, ok)
 	}
 	if text, ok := ParseTerminalSequence("plain"); ok || text.Type != "" {
 		t.Fatalf("plain dispatch = %#v ok=%v", text, ok)

internal/tui/tui_test.go

@@ -5743,8 +5743,9 @@ func TestParseESCSequenceActions(t *testing.T) {
 	if action, ok := ParseESCContent(""); ok || action.Type != "" {
 		t.Fatalf("empty esc content parsed = %#v", action)
 	}
-	if action, ok := ParseESCSequence("\x1b(B"); ok || action.Type != "" {
-		t.Fatalf("charset selection should be ignored = %#v", action)
+	charset, ok := ParseESCSequence("\x1b(B")
+	if !ok || charset.Type != ESCActionCharset || charset.CharsetSlot != '(' || charset.CharsetDesignator != 'B' {
+		t.Fatalf("charset selection = %#v ok=%v", charset, ok)
 	}
 
 	reset, ok := ParseESCSequence(ESCResetSequence)