fix: forward browser terminal pastes as bracketed input

- Track application bracketed-paste mode from terminal output.
- Capture browser and mobile clipboard pastes only while that mode is enabled,
  normalizing line endings and sending a single BPM-framed input event.
- Remove the synchronous output decoding and console diagnostics that could
  stall terminal rendering under output load.
- Keep the terminal's zero-scrollback configuration and resolve existing
  no-case-declarations lint blockers in terminal keyboard shortcuts.

Quality gates: npm run typecheck, npm run lint

apps/web/src/components/features/terminal/terminal.tsx

@@ -48,6 +48,18 @@ const MIN_FONT_SIZE = 4;
 const MAX_FONT_SIZE = 24;
 const RECONNECT_ATTEMPTS = 3;
 const RECONNECT_DELAY_BASE = 1000;
+const BRACKETED_PASTE_ENABLE_SEQUENCE = [0x1b, 0x5b, 0x3f, 0x32, 0x30, 0x30, 0x34, 0x68];
+const BRACKETED_PASTE_DISABLE_SEQUENCE = [0x1b, 0x5b, 0x3f, 0x32, 0x30, 0x30, 0x34, 0x6c];
+const BRACKETED_PASTE_CONTROL_TAIL_LENGTH =
+	BRACKETED_PASTE_ENABLE_SEQUENCE.length - 1;
+
+function matchesByteSequence(
+	data: Uint8Array,
+	start: number,
+	sequence: readonly number[],
+): boolean {
+	return sequence.every((byte, index) => data[start + index] === byte);
+}
 
 export const TerminalComponent = React.forwardRef<TerminalRef, TerminalProps>(
 	(
@@ -68,6 +80,8 @@ export const TerminalComponent = React.forwardRef<TerminalRef, TerminalProps>(
 		const wsRef = useRef<WebSocket | null>(null);
 		const termRef = useRef<Terminal | null>(null);
 		const fitAddonRef = useRef<FitAddon | null>(null);
+		const bracketedPasteEnabledRef = useRef(false);
+		const pasteTextRef = useRef<(text: string) => void>(() => {});
 		const reconnectAttemptsRef = useRef(0);
 		const onTerminalReadyRef = useRef(onTerminalReady);
 		onTerminalReadyRef.current = onTerminalReady;
@@ -111,6 +125,41 @@ export const TerminalComponent = React.forwardRef<TerminalRef, TerminalProps>(
 			ws.binaryType = "arraybuffer";
 			wsRef.current = ws;
 
+			let bracketedPasteControlTail = new Uint8Array(0);
+			const updateBracketedPasteMode = (data: Uint8Array) => {
+				const combined = new Uint8Array(
+					bracketedPasteControlTail.length + data.length,
+				);
+				combined.set(bracketedPasteControlTail);
+				combined.set(data, bracketedPasteControlTail.length);
+
+				for (let index = 0; index < combined.length; index++) {
+					if (
+						index + BRACKETED_PASTE_ENABLE_SEQUENCE.length <= combined.length &&
+						matchesByteSequence(
+							combined,
+							index,
+							BRACKETED_PASTE_ENABLE_SEQUENCE,
+						)
+					) {
+						bracketedPasteEnabledRef.current = true;
+					} else if (
+						index + BRACKETED_PASTE_DISABLE_SEQUENCE.length <= combined.length &&
+						matchesByteSequence(
+							combined,
+							index,
+							BRACKETED_PASTE_DISABLE_SEQUENCE,
+						)
+					) {
+						bracketedPasteEnabledRef.current = false;
+					}
+				}
+
+				bracketedPasteControlTail = combined.slice(
+					Math.max(0, combined.length - BRACKETED_PASTE_CONTROL_TAIL_LENGTH),
+				);
+			};
+
 			ws.onopen = () => {
 				setStatus("connected");
 				setError(null);
@@ -156,14 +205,9 @@ export const TerminalComponent = React.forwardRef<TerminalRef, TerminalProps>(
 
 				if (event.data instanceof ArrayBuffer) {
 					const data = new Uint8Array(event.data);
+					updateBracketedPasteMode(data);
 					termRef.current.write(data);
 
-					// TEMP diagnostic: log when pi's bracketed-paste enable sequence reaches xterm
-					const text = new TextDecoder().decode(data);
-					if (text.includes("\x1b[?2004h")) {
-						console.log("[BPMDIAG] enable sequence (\\e[?2004h) reached xterm");
-					}
-
 					// Flow control: accumulate processed bytes
 					ackAccumulator += data.length;
 					if (ackAccumulator >= ACK_THRESHOLD) {
@@ -289,7 +333,7 @@ export const TerminalComponent = React.forwardRef<TerminalRef, TerminalProps>(
 				// the mouse-wheel scrolls through stale frames instead of the app.
 				// scrollback:0 keeps only the live viewport: no bar, no stale-frame
 				// wheel jank. (Scrollbar is also hidden via CSS for belt-and-suspenders.)
-				scrollback: 10000,
+				scrollback: 0,
 				ignoreBracketedPasteMode: false,
 				fastScrollSensitivity: 0,
 				scrollSensitivity: 0,
@@ -367,6 +411,32 @@ export const TerminalComponent = React.forwardRef<TerminalRef, TerminalProps>(
 			term.focus();
 			const ws = connectWebSocket();
 
+			pasteTextRef.current = (text: string) => {
+				const currentWs = wsRef.current;
+				if (currentWs?.readyState !== WebSocket.OPEN) return;
+
+				if (bracketedPasteEnabledRef.current) {
+					const normalizedText = text.replace(/\r\n|\r|\n/g, "\r");
+					currentWs.send(`\x1b[200~${normalizedText}\x1b[201~`);
+					return;
+				}
+
+				term.paste(text);
+			};
+
+			const handleBrowserPaste = (event: ClipboardEvent) => {
+				if (!bracketedPasteEnabledRef.current) return;
+				const text = event.clipboardData?.getData("text/plain");
+				if (text === undefined || wsRef.current?.readyState !== WebSocket.OPEN) {
+					return;
+				}
+
+				event.preventDefault();
+				event.stopImmediatePropagation();
+				pasteTextRef.current(text);
+			};
+			container.addEventListener("paste", handleBrowserPaste, true);
+
 			// Mobile touch scroll.
 			// In normal mode xterm.js has a scrollable viewport; in alternate
 			// screen (tmux/vim) there is no scrollback and the only way to
@@ -506,12 +576,6 @@ export const TerminalComponent = React.forwardRef<TerminalRef, TerminalProps>(
 
 			// Handle terminal input
 			term.onData((data) => {
-				// TEMP diagnostic: log paste-like outbound data and whether BPM-wrapped
-				if (data.length > 10 && (data.includes("\n") || data.includes("\r"))) {
-					const bpmWrapped = data.startsWith("\x1b[200~") && data.endsWith("\x1b[201~");
-					console.log("[PASTEDIAG] bpmWrapped=" + bpmWrapped + " len=" + data.length);
-				}
-
 				const currentWs = wsRef.current;
 				if (currentWs?.readyState !== WebSocket.OPEN) return;
 
@@ -619,6 +683,9 @@ export const TerminalComponent = React.forwardRef<TerminalRef, TerminalProps>(
 					handleVisibilityChange,
 				);
 				if (touchCleanup) touchCleanup();
+				container.removeEventListener("paste", handleBrowserPaste, true);
+				pasteTextRef.current = () => {};
+				bracketedPasteEnabledRef.current = false;
 				if (ws) {
 					ws.close(1000, "Component unmounting");
 				}
@@ -740,14 +807,7 @@ export const TerminalComponent = React.forwardRef<TerminalRef, TerminalProps>(
 
 		const handlePaste = async () => {
 			try {
-				const text = await navigator.clipboard.readText();
-				// Route through xterm.js instead of sending raw text directly.
-				// term.paste() wraps the content in bracketed-paste markers
-				// (\e[200~...\e[201~) when the app has enabled BPM, so multiline
-				// pastes arrive as a single input rather than one prompt per line.
-				// It emits via onData, which the existing handler forwards to the
-				// WebSocket, so the readyState check happens there.
-				termRef.current?.paste(text);
+				pasteTextRef.current(await navigator.clipboard.readText());
 			} catch {
 				// Clipboard API not available
 			}