FN-5885: fix terminal copy/paste shortcuts

Restore expected terminal clipboard shortcuts.

- intercept Ctrl/Cmd+C in the dashboard terminal to copy the current selection while preserving plain SIGINT when nothing is selected
- intercept Ctrl/Cmd+V to read clipboard text and send it into the active PTY session
- add terminal shortcut regression coverage and document the new integrated terminal behavior
- add a patch changeset for @runfusion/fusion

Files changed:
 .changeset/friendly-ravens-hammer.md               |   5 +
 docs/dashboard-guide.md                            |   2 +
 packages/dashboard/app/components/TerminalModal.tsx     |  48 +++++++++
 packages/dashboard/app/components/__tests__/TerminalModal.test.tsx    | 113 +++++++++++++++++++++
 4 files changed, 168 insertions(+)

Fusion-Task-Id: FN-5885

Fusion-Task-Lineage: f8b3658c-2b52-4094-8cef-79c762f4d78d

packages/dashboard/app/components/TerminalModal.tsx

@@ -161,6 +161,16 @@ function isMobileDevice(): boolean {
   return hasTouchScreen && isNarrow;
 }
 
+function isMacPlatform(): boolean {
+  if (typeof navigator === "undefined") {
+    return false;
+  }
+
+  const platform = navigator.platform ?? "";
+  const userAgent = navigator.userAgent ?? "";
+  return /mac/i.test(platform) || /mac/i.test(userAgent);
+}
+
 /**
  * Compute how many CSS pixels the virtual keyboard covers from the bottom
  * of the layout viewport. Returns 0 on desktop or when visualViewport is
@@ -649,6 +659,44 @@ export function TerminalModal({ isOpen, onClose, initialCommand, projectId }: Te
           sendInputRef.current(data);
         });
 
+        terminal.attachCustomKeyEventHandler((event) => {
+          if (event.type !== "keydown") {
+            return true;
+          }
+
+          const isModifierPressed = isMacPlatform() ? event.metaKey : event.ctrlKey;
+          if (!isModifierPressed || event.altKey || event.shiftKey) {
+            return true;
+          }
+
+          const key = event.key.toLowerCase();
+
+          if (key === "c") {
+            const selection = terminal.hasSelection() ? terminal.getSelection() : "";
+            if (!selection) {
+              return true;
+            }
+
+            navigator.clipboard?.writeText(selection).catch(() => {
+              // Ignore clipboard permission/errors so terminal input stays responsive.
+            });
+            return false;
+          }
+
+          if (key === "v") {
+            navigator.clipboard?.readText().then((text) => {
+              if (text) {
+                sendInputRef.current(text);
+              }
+            }).catch(() => {
+              // Ignore clipboard permission/errors so terminal input stays responsive.
+            });
+            return false;
+          }
+
+          return true;
+        });
+
         // Window resize listener bound to this xterm. Tracked in a ref so it
         // can be removed when xterm is disposed (modal close, tab switch).
         const resizeHandler = () => {

packages/dashboard/app/components/__tests__/TerminalModal.test.tsx

@@ -23,10 +23,18 @@ vi.mock("../../api", () => ({
 // Mock xterm modules to prevent DOM errors in jsdom
 const mockFitAddonFit = vi.fn();
 
+let terminalKeyEventHandler: ((event: KeyboardEvent) => boolean) | null = null;
+
 const mockTerminalInstance = {
   loadAddon: vi.fn(),
   open: vi.fn(),
   onData: vi.fn((_cb: (data: string) => void) => ({ dispose: vi.fn() })),
+  attachCustomKeyEventHandler: vi.fn((handler: (event: KeyboardEvent) => boolean) => {
+    terminalKeyEventHandler = handler;
+  }),
+  hasSelection: vi.fn(() => false),
+  getSelection: vi.fn(() => ""),
+  paste: vi.fn(),
   dispose: vi.fn(),
   write: vi.fn(),
   clear: vi.fn(),
@@ -122,7 +130,18 @@ describe("TerminalModal", () => {
 
   beforeEach(() => {
     vi.clearAllMocks();
+    terminalKeyEventHandler = null;
     mockFitAddonFit.mockClear();
+    mockTerminalInstance.hasSelection.mockReturnValue(false);
+    mockTerminalInstance.getSelection.mockReturnValue("");
+    Object.defineProperty(navigator, "platform", {
+      value: "Win32",
+      configurable: true,
+    });
+    Object.defineProperty(navigator, "clipboard", {
+      value: undefined,
+      configurable: true,
+    });
     window.localStorage.removeItem(TERMINAL_FONT_SIZE_KEY);
     mockTerminalInstance.options.fontSize = 14;
     mockCreateTerminalSession.mockResolvedValue({
@@ -3993,6 +4012,100 @@ describe("TerminalModal — xterm focus initialization (FN-1602)", () => {
     expect(mockSendInput).toHaveBeenCalledWith("echo hello\r");
   });
 
+  it("copies selected terminal text on ctrl+c and blocks sigint", async () => {
+    const writeText = vi.fn().mockResolvedValue(undefined);
+    Object.defineProperty(navigator, "platform", {
+      value: "Win32",
+      configurable: true,
+    });
+    Object.defineProperty(navigator, "clipboard", {
+      value: { writeText },
+      configurable: true,
+    });
+    mockTerminalInstance.hasSelection.mockReturnValue(true);
+    mockTerminalInstance.getSelection.mockReturnValue("copied output");
+
+    render(<TerminalModal isOpen={true} onClose={mockOnClose} />);
+
+    await waitFor(() => {
+      expect(terminalKeyEventHandler).not.toBeNull();
+    });
+
+    const handled = terminalKeyEventHandler?.(
+      new KeyboardEvent("keydown", { key: "c", ctrlKey: true }),
+    );
+
+    expect(handled).toBe(false);
+    expect(writeText).toHaveBeenCalledWith("copied output");
+    expect(mockSendInput).not.toHaveBeenCalled();
+  });
+
+  it("preserves sigint on ctrl+c when nothing is selected", async () => {
+    Object.defineProperty(navigator, "platform", {
+      value: "Win32",
+      configurable: true,
+    });
+    Object.defineProperty(navigator, "clipboard", {
+      value: { writeText: vi.fn().mockResolvedValue(undefined) },
+      configurable: true,
+    });
+    mockTerminalInstance.hasSelection.mockReturnValue(false);
+
+    render(<TerminalModal isOpen={true} onClose={mockOnClose} />);
+
+    await waitFor(() => {
+      expect(terminalKeyEventHandler).not.toBeNull();
+    });
+
+    const handled = terminalKeyEventHandler?.(
+      new KeyboardEvent("keydown", { key: "c", ctrlKey: true }),
+    );
+
+    expect(handled).toBe(true);
+  });
+
+  it("pastes clipboard text into the active session on cmd+v", async () => {
+    const readText = vi.fn().mockResolvedValue("npm test\n");
+    Object.defineProperty(navigator, "platform", {
+      value: "MacIntel",
+      configurable: true,
+    });
+    Object.defineProperty(navigator, "clipboard", {
+      value: { readText },
+      configurable: true,
+    });
+
+    render(<TerminalModal isOpen={true} onClose={mockOnClose} />);
+
+    await waitFor(() => {
+      expect(terminalKeyEventHandler).not.toBeNull();
+    });
+
+    const handled = terminalKeyEventHandler?.(
+      new KeyboardEvent("keydown", { key: "v", metaKey: true }),
+    );
+
+    expect(handled).toBe(false);
+    await waitFor(() => {
+      expect(readText).toHaveBeenCalled();
+      expect(mockSendInput).toHaveBeenCalledWith("npm test\n");
+    });
+  });
+
+  it("leaves unrelated key handling untouched", async () => {
+    render(<TerminalModal isOpen={true} onClose={mockOnClose} />);
+
+    await waitFor(() => {
+      expect(terminalKeyEventHandler).not.toBeNull();
+    });
+
+    const handled = terminalKeyEventHandler?.(
+      new KeyboardEvent("keydown", { key: "x", ctrlKey: true }),
+    );
+
+    expect(handled).toBe(true);
+  });
+
   it("keeps terminal input forwarding active after active-tab title rerenders", async () => {
     let terminalInputCallback: ((data: string) => void) | null = null;
     const disposeInputHandler = vi.fn();