fix(coding-agent): spawn the WSL text clipboard read async and route the text fallback by focus

Address review notes on #2248:

- readTextFromClipboard's WSL branch now mirrors readImageViaPowerShell
  (Bun.spawn + kill timer sharing POWERSHELL_TIMEOUT_MS) instead of
  execSync, so a cold powershell.exe start cannot block the TUI event
  loop on the first smart-paste miss.
- The smart-paste text fallback routes through ui.getFocused() +
  hasPasteText like the enhanced-paste text path, so the payload lands
  in focused modal Input prompts instead of the hidden main editor
  (#2127 contract). Covered by a new routing test.

packages/coding-agent/src/modes/controllers/input-controller.ts

@@ -840,7 +840,11 @@ export class InputController {
 					this.ctx.showStatus("Clipboard is empty");
 					return false;
 				}
-				this.ctx.editor.pasteText(text);
+				// Route to the focused component when it accepts pastes (modal
+				// Input prompts), matching the enhanced-paste text path (#2127).
+				const focused = this.ctx.ui.getFocused();
+				const target = focused && focused !== this.ctx.editor && hasPasteText(focused) ? focused : this.ctx.editor;
+				target.pasteText(text);
 				this.ctx.ui.requestRender();
 				return true;
 			}

packages/coding-agent/src/utils/clipboard.ts

@@ -125,6 +125,53 @@ async function readImageViaPowerShell(): Promise<ClipboardImage | null> {
 	}
 }
 
+// PowerShell one-liner that emits the clipboard text verbatim on stdout, or
+// nothing when the clipboard holds no text. `[Console]::Out.Write` avoids the
+// trailing newline Write-Output would add; output encoding is forced to UTF-8
+// so non-ASCII text survives the interop boundary regardless of console
+// codepage.
+const POWERSHELL_TEXT_SCRIPT = `
+$ErrorActionPreference = 'Stop'
+[Console]::OutputEncoding = [Text.Encoding]::UTF8
+[Console]::Out.Write([string](Get-Clipboard -Raw))
+`;
+
+/**
+ * Read clipboard text through the Windows host's PowerShell.
+ *
+ * Same rationale as `readImageViaPowerShell`: WSLg's Wayland clipboard only
+ * works when `wl-clipboard` happens to be installed in the distro, while
+ * `powershell.exe` is always reachable over WSL interop. Spawned async so a
+ * cold PowerShell start cannot block the TUI event loop.
+ *
+ * Returns null when the bridge fails (caller falls through to wl-paste/xclip);
+ * an empty string is a successful "no text on the clipboard" read.
+ */
+async function readTextViaPowerShell(): Promise<string | null> {
+	try {
+		const proc = Bun.spawn(["powershell.exe", "-NoProfile", "-NonInteractive", "-Command", POWERSHELL_TEXT_SCRIPT], {
+			stdout: "pipe",
+			stderr: "ignore",
+			stdin: "ignore",
+		});
+		const timer = setTimeout(() => proc.kill(), POWERSHELL_TIMEOUT_MS);
+		let stdout = "";
+		try {
+			stdout = await new Response(proc.stdout).text();
+			await proc.exited;
+		} catch (err) {
+			logger.warn("clipboard: powershell text read failed", { error: String(err) });
+			return null;
+		} finally {
+			clearTimeout(timer);
+		}
+		if (proc.exitCode !== 0) return null;
+		return stdout.replaceAll("\r\n", "\n");
+	} catch {
+		return null;
+	}
+}
+
 /**
  * Read an image from the system clipboard.
  *
@@ -174,20 +221,9 @@ export async function readTextFromClipboard(): Promise<string> {
 			return execSync("termux-clipboard-get", { encoding: "utf8", timeout: 2000 }).toString();
 		}
 		if (isWsl()) {
-			try {
-				// Reach the Windows clipboard through host PowerShell, mirroring
-				// readImageFromClipboard: WSLg's wl-paste only works when
-				// wl-clipboard happens to be installed in the distro, while
-				// powershell.exe is always reachable over WSL interop.
-				return execSync(
-					'powershell.exe -NoProfile -NonInteractive -Command "[Console]::OutputEncoding=[Text.Encoding]::UTF8; [Console]::Out.Write([string](Get-Clipboard -Raw))"',
-					{ encoding: "utf8", timeout: 5000 },
-				)
-					.toString()
-					.replaceAll("\r\n", "\n");
-			} catch {
-				// Fall through to the wl-paste/xclip paths below.
-			}
+			const text = await readTextViaPowerShell();
+			if (text !== null) return text;
+			// Bridge failed — fall through to the wl-paste/xclip paths below.
 		}
 		const hasWaylandDisplay = Boolean(process.env.WAYLAND_DISPLAY);
 		const hasX11Display = Boolean(process.env.DISPLAY);

packages/coding-agent/test/input-controller-smart-paste.test.ts

@@ -10,14 +10,14 @@ import { describe, expect, it, vi } from "bun:test";
 import { InputController } from "@oh-my-pi/pi-coding-agent/modes/controllers/input-controller";
 import type { InteractiveModeContext } from "@oh-my-pi/pi-coding-agent/modes/types";
 
-function createContext() {
+function createContext(options?: { focused?: { pasteText(text: string): void } }) {
 	const pasteText = vi.fn();
 	const insertText = vi.fn();
 	const requestRender = vi.fn();
 	const showStatus = vi.fn();
 	const ctx = {
 		editor: { pasteText, insertText } as unknown as InteractiveModeContext["editor"],
-		ui: { requestRender } as unknown as InteractiveModeContext["ui"],
+		ui: { requestRender, getFocused: () => options?.focused ?? null } as unknown as InteractiveModeContext["ui"],
 		showStatus,
 	} as unknown as InteractiveModeContext;
 	return { ctx, spies: { pasteText, insertText, requestRender, showStatus } };
@@ -58,6 +58,21 @@ describe("InputController.handleImagePaste smart-paste fallback", () => {
 		expect(spies.showStatus).not.toHaveBeenCalled();
 	});
 
+	it("routes the text fallback to a focused paste-capable component (#2127 contract)", async () => {
+		const focusedPasteText = vi.fn();
+		const { ctx, spies } = createContext({ focused: { pasteText: focusedPasteText } });
+		const controller = new InputController(ctx, {
+			readImage: async () => null,
+			readText: async () => "api-key-123",
+		});
+
+		const result = await controller.handleImagePaste();
+
+		expect(result).toBe(true);
+		expect(focusedPasteText).toHaveBeenCalledWith("api-key-123");
+		expect(spies.pasteText).not.toHaveBeenCalled();
+	});
+
 	it("reports an empty clipboard when neither image nor text is available", async () => {
 		const { ctx, spies } = createContext();
 		const controller = new InputController(ctx, {