fix(mcp): hid windows cmd stdio shims

Wrap Windows MCP .cmd/.bat stdio launches through a hidden cmd.exe invocation so PATH shims such as npx keep stdio attached without flashing a console.

Fixes #2287

packages/coding-agent/CHANGELOG.md

@@ -163,7 +163,7 @@
 - Fixed pasting into the ask tool's "Other (type your own)" text box (and hook input/editor dialogs) on terminals with OSC 5522 enhanced paste (kitty protocol): the enhanced-paste focus routing only targets components exposing a `pasteText` hook, and the dialog wrappers had none, so the payload was stuffed into the main prompt editor hidden behind the dialog. `HookEditorComponent` and `HookInputComponent` now forward `pasteText` to their inner editor/input (pasting also resets the input dialog's timeout countdown like any keystroke).
 - Fixed auto-retry giving up after one attempt ("Provider requested Xms wait, exceeds retry.maxDelayMs") on a usage-limit 429 when every sibling account was only momentarily blocked: the retry delay now waits for the earliest sibling unblock when that comes sooner than the provider's multi-hour retry-after, so the next attempt picks up the recovered account instead of failing fast.
 - Fixed Hindsight `per-project-tagged` mental-model seeding so each project gets its own conventions/decisions models and session context only injects active-project or untagged models ([#2218](https://github.com/can1357/oh-my-pi/issues/2218)).
-- Fixed Windows stdio MCP `.cmd` commands by wrapping batch shims with `cmd.exe /d /s /c` using the outer command quotes required by `cmd /s`, while preserving literal `%` and quoted JSON arguments for Codegraph MCP ([#2220](https://github.com/can1357/oh-my-pi/issues/2220)).
+- Fixed Windows stdio MCP `.cmd` commands by wrapping batch shims such as `npx.cmd` and `codegraph.cmd` with hidden `cmd.exe /d /s /c` launches using the outer command quotes required by `cmd /s`, while preserving literal `%` and quoted JSON arguments ([#2220](https://github.com/can1357/oh-my-pi/issues/2220), [#2287](https://github.com/can1357/oh-my-pi/issues/2287)).
 - Fixed the bundled `explore` agent's `thinking-level: med` frontmatter — not a valid effort (`minimal`/`low`/`medium`/`high`/`xhigh`), so it silently parsed to undefined and the agent ran without its intended thinking level
 - Discovery context-file reads (`~/.claude`, `~/.cursor`, project trees, `@`-imports) now stat-gate to regular files before reading: a FIFO/socket/char device dropped where a context file is expected previously blocked startup forever on a read that can never see EOF.
 - Fixed the read tool's provider-visible `path` schema and docs so web URLs and internal URI targets (`omp://`, `issue://`, `pr://`, etc.) are advertised alongside local files ([#2215](https://github.com/can1357/oh-my-pi/issues/2215)).

packages/coding-agent/src/mcp/transports/stdio.ts

@@ -25,6 +25,7 @@ import { isMCPTimeoutEnabled, resolveMCPTimeoutMs } from "../timeout";
 /** Subprocess argv for launching an MCP stdio server. */
 export interface StdioSpawnCommand {
 	cmd: string[];
+	windowsHide?: boolean;
 }
 
 /** Inputs used to resolve platform-specific stdio spawn behavior. */
@@ -153,6 +154,7 @@ export async function resolveStdioSpawnCommand(
 
 	return {
 		cmd: [resolveComSpec(options.env), "/d", "/s", "/c", buildCmdExeCommand(resolvedCommand, args)],
+		windowsHide: true,
 	};
 }
 
@@ -255,6 +257,7 @@ export class StdioTransport implements MCPTransport {
 			stdin: "pipe",
 			stdout: "pipe",
 			stderr: "pipe",
+			windowsHide: spawnCommand.windowsHide,
 		});
 
 		this.#connected = true;

packages/coding-agent/test/mcp-stdio-transport.test.ts

@@ -32,6 +32,7 @@ describe("resolveStdioSpawnCommand", () => {
 				"/c",
 				`""${shim}" "serve" "--mcp""`,
 			]);
+			expect(result.windowsHide).toBe(true);
 		} finally {
 			await fs.rm(tempDir, { recursive: true, force: true });
 		}
@@ -63,6 +64,7 @@ describe("resolveStdioSpawnCommand", () => {
 				"/c",
 				`""${shim}" "serve" "--header" "Authorization=^%TOKEN^%""`,
 			]);
+			expect(result.windowsHide).toBe(true);
 		} finally {
 			await fs.rm(tempDir, { recursive: true, force: true });
 		}
@@ -94,6 +96,7 @@ describe("resolveStdioSpawnCommand", () => {
 				"/c",
 				`""${shim}" "--config" "{^"a^":^"b&c|d^"}""`,
 			]);
+			expect(result.windowsHide).toBe(true);
 		} finally {
 			await fs.rm(tempDir, { recursive: true, force: true });
 		}
@@ -133,6 +136,7 @@ describe("resolveStdioSpawnCommand", () => {
 				"/c",
 				`""${shim}" "serve" "--mcp""`,
 			]);
+			expect(result.windowsHide).toBe(true);
 		} finally {
 			await fs.rm(tempDir, { recursive: true, force: true });
 		}
@@ -159,6 +163,7 @@ describe("resolveStdioSpawnCommand", () => {
 			"/c",
 			`""codegraph.cmd" "serve" "--mcp""`,
 		]);
+		expect(result.windowsHide).toBe(true);
 	});
 
 	it("leaves non-Windows commands untouched", async () => {
@@ -168,6 +173,7 @@ describe("resolveStdioSpawnCommand", () => {
 		);
 
 		expect(result.cmd).toEqual(["codegraph", "serve", "--mcp"]);
+		expect(result.windowsHide).toBeUndefined();
 	});
 });