fix(install): always install .cursor client and refresh setups on upgrade

docs/ironbee-vscode-design.md

@@ -508,14 +508,15 @@ could disrupt projects the user never intended to touch, and verification settin
   `verification.checks` are chosen **per project** via QuickPick (or the folder's existing
   `<folder>/.ironbee/config.json` if re-running), written to that folder's committed
   `.ironbee/config.json`.
-- **AI-client selection — default to `.cursor` when nothing is detected.** Detect existing client
-  dirs per folder (`.cursor`/`.claude`/`.codex`) and target the detected one(s). **If none of the
-  three exist, this being a Cursor extension, install into `.cursor`** by passing `--client cursor`
-  **explicitly**. ⚠ Do NOT rely on the CLI's own no-detection fallback: `REGISTERED_CLIENTS[0]` is
-  **`claude`** (`ironbee-cli/src/clients/registry.ts:10-14,88`), so an unqualified install would
-  land in `.claude`, not `.cursor`. `cursor` is a valid `--client` value
-  (`clients/cursor/index.ts:162`). (If the host is VS Code proper rather than Cursor, still default
-  to the detected client, or `cursor` if the extension standardizes on it.)
+- **AI-client selection — install into `.cursor` ONLY, always.** This being a Cursor extension,
+  every install targets exactly **`cursor`**: `.cursor` is created if missing and updated
+  in-place if present (the CLI merges — only IronBee-owned entries in `mcp.json`/`hooks.json`/
+  `permissions.json` and `ironbee-*` files are written; the user's own entries are preserved).
+  Existing `.claude`/`.codex` dirs are **never touched** — no IronBee files are written into
+  them, nothing is removed from them. `cursor` is passed as `--client cursor` **explicitly**.
+  ⚠ Do NOT rely on the CLI's own no-detection fallback: `REGISTERED_CLIENTS[0]` is **`claude`**
+  (`ironbee-cli/src/clients/registry.ts:10-14,88`), so an unqualified install would land in
+  `.claude`, not `.cursor`. `cursor` is a valid `--client` value (`clients/cursor/index.ts:162`).
 - **LLM-driven platform suggestion (best-effort, reuses IronBee's own mechanism — NOT the
   editor's LLM API).** The platform QuickPick offers a "Suggest platforms" affordance that
   pre-selects platforms based on the project. The suggestion is produced by running the user's

src/runtime/clientDetect.ts

@@ -1,45 +1,15 @@
-import { promises as fs } from 'node:fs';
-import type { Stats } from 'node:fs';
-import * as path from 'node:path';
-
 export type AiClient = 'cursor' | 'claude' | 'codex';
 
-/** Marker dir each AI client uses inside a project. */
-const CLIENT_DIRS: Record<AiClient, string> = {
-    cursor: '.cursor',
-    claude: '.claude',
-    codex: '.codex',
-};
-
-/** All clients whose marker dir already exists in the folder. */
-export async function detectClients(folderDir: string): Promise<AiClient[]> {
-    const found: AiClient[] = [];
-    for (const client of Object.keys(CLIENT_DIRS) as AiClient[]) {
-        if (await dirExists(path.join(folderDir, CLIENT_DIRS[client]))) {
-            found.push(client);
-        }
-    }
-    return found;
-}
-
 /**
  * Which client(s) `ironbee install` should target for a folder.
  *
- * If any client dir exists, target those. If **none** exists, default to
- * **`cursor`** (this is a Cursor extension) — passed EXPLICITLY as `--client cursor`.
- * We must NOT rely on the CLI's own no-detection fallback: `REGISTERED_CLIENTS[0]`
- * is `claude`, so an unqualified install would land in `.claude` (design EXT-6).
+ * Always exactly **`cursor`** — this is a Cursor extension: it wires up only the editor the user
+ * is sitting in and NEVER writes into `.claude`/`.codex`, even when those dirs exist (other
+ * tools' setups are left completely untouched). `cursor` is passed EXPLICITLY as
+ * `--client cursor`: we must NOT rely on the CLI's own no-detection fallback, whose
+ * `REGISTERED_CLIENTS[0]` is `claude`, so an unqualified install would land in `.claude`
+ * (design EXT-6).
  */
-export async function resolveInstallClients(folderDir: string): Promise<AiClient[]> {
-    const detected: AiClient[] = await detectClients(folderDir);
-    return detected.length > 0 ? detected : ['cursor'];
-}
-
-async function dirExists(p: string): Promise<boolean> {
-    try {
-        const st: Stats = await fs.stat(p);
-        return st.isDirectory();
-    } catch {
-        return false;
-    }
+export function resolveInstallClients(): AiClient[] {
+    return ['cursor'];
 }

src/ui/setupFlow.ts

@@ -20,7 +20,7 @@ export interface FolderOutcome {
 /**
  * Set up ONE folder with a pre-chosen `mode` (design EXT-6). Platforms are chosen per folder
  * (each project's structure differs) via `deps.pickPlatforms`; then install once per resolved
- * client (defaults to `.cursor` when none is detected).
+ * client (always exactly `.cursor`; existing `.claude`/`.codex` setups are never touched).
  */
 export async function setUpFolder(
     folderDir: string,
@@ -32,7 +32,7 @@ export async function setUpFolder(
         return { folder: folderDir, cancelled: true, installed: [], failed: [] };
     }
 
-    const clients: AiClient[] = await resolveInstallClients(folderDir);
+    const clients: AiClient[] = resolveInstallClients();
     const installed: AiClient[] = [];
     const failed: AiClient[] = [];
     for (const client of clients) {

test/live.test.ts

@@ -33,7 +33,7 @@ describe.runIf(LIVE)('LIVE: ironbee install', () => {
             // The extension writes this to global config so npx-devtools never downloads browsers.
             await writeDevtoolsEnv({ PLAYWRIGHT_SKIP_BROWSER_DOWNLOAD: '1', BROWSER_DEVTOOLS_INSTALL_CHROMIUM: 'false' });
 
-            expect(await resolveInstallClients(proj)).toEqual(['cursor']);
+            expect(resolveInstallClients()).toEqual(['cursor']);
 
             const res = await runInstall(
                 { nodePath: process.execPath, cliEntry },

test/runtime/clientDetect.test.ts

@@ -1,45 +1,8 @@
-import { describe, it, expect, beforeEach, afterEach } from 'vitest';
-import { promises as fs } from 'node:fs';
-import * as os from 'node:os';
-import * as path from 'node:path';
-import { detectClients, resolveInstallClients } from '../../src/runtime/clientDetect';
-
-let dir: string;
-
-beforeEach(async () => {
-    dir = await fs.mkdtemp(path.join(os.tmpdir(), 'ib-detect-'));
-});
-afterEach(async () => {
-    await fs.rm(dir, { recursive: true, force: true });
-});
-
-describe('detectClients', () => {
-    it('returns empty when no client dirs exist', async () => {
-        expect(await detectClients(dir)).toEqual([]);
-    });
-
-    it('detects each present client dir', async () => {
-        await fs.mkdir(path.join(dir, '.claude'));
-        await fs.mkdir(path.join(dir, '.codex'));
-        const found = await detectClients(dir);
-        expect(found).toContain('claude');
-        expect(found).toContain('codex');
-        expect(found).not.toContain('cursor');
-    });
-
-    it('ignores a same-named file (must be a directory)', async () => {
-        await fs.writeFile(path.join(dir, '.cursor'), 'not a dir');
-        expect(await detectClients(dir)).toEqual([]);
-    });
-});
+import { describe, it, expect } from 'vitest';
+import { resolveInstallClients } from '../../src/runtime/clientDetect';
 
 describe('resolveInstallClients', () => {
-    it('defaults to cursor when nothing is detected', async () => {
-        expect(await resolveInstallClients(dir)).toEqual(['cursor']);
-    });
-
-    it('targets detected clients when present', async () => {
-        await fs.mkdir(path.join(dir, '.claude'));
-        expect(await resolveInstallClients(dir)).toEqual(['claude']);
+    it('always targets exactly cursor — never claude/codex, regardless of what exists in the folder', () => {
+        expect(resolveInstallClients()).toEqual(['cursor']);
     });
 });

test/ui/setupFlow.test.ts

@@ -44,10 +44,10 @@ describe('setUpFolder', () => {
         expect(out.cancelled).toBe(false);
     });
 
-    it('installs into a detected client instead of cursor', async () => {
+    it('installs ONLY into cursor even when .claude exists (other clients are never touched)', async () => {
         await fs.mkdir(path.join(dir, '.claude'));
         const out = await setUpFolder(dir, 'assist', deps(async () => ['node']));
-        expect(out.installed).toEqual(['claude']);
+        expect(out.installed).toEqual(['cursor']);
     });
 
     it('cancels (no install) when the platform pick is cancelled', async () => {