diff --git a/src/main/index.ts b/src/main/index.ts
index 2ee7c6c1..02bb817c 100644
--- a/src/main/index.ts
+++ b/src/main/index.ts
@@ -793,7 +793,7 @@ function initializeServices(): void {
   const glamaMcpService = new GlamaMcpEnrichmentService();
   const mcpAggregator = new McpCatalogAggregator(officialMcpRegistry, glamaMcpService);
   const mcpStateService = new McpInstallationStateService();
-  const mcpHealthDiagnosticsService = new McpHealthDiagnosticsService(null);
+  const mcpHealthDiagnosticsService = new McpHealthDiagnosticsService();
   const skillsCatalogService = new SkillsCatalogService();
   const skillsMutationService = new SkillsMutationService();
   skillsWatcherService = new SkillsWatcherService();
@@ -804,9 +804,9 @@ function initializeServices(): void {
     mcpStateService
   );
 
-  // Install services — pass null for binary (uses PATH lookup via execCli fallback)
-  const pluginInstallService = new PluginInstallService(null, pluginCatalogService);
-  const mcpInstallService = new McpInstallService(null, mcpAggregator);
+  // Install services — resolve binary dynamically via ClaudeBinaryResolver
+  const pluginInstallService = new PluginInstallService(pluginCatalogService);
+  const mcpInstallService = new McpInstallService(mcpAggregator);
   const apiKeyService = new ApiKeyService();
   // warmup() and ensureInstalled() are deferred to after window creation
   // (did-finish-load handler) to avoid thread pool contention at startup.
@@ -1167,6 +1167,7 @@ function createWindow(): void {
       }
 
       setTimeout(() => updaterService.checkForUpdates(), 3000);
+      updaterService.startPeriodicCheck(60 * 60 * 1000);
 
       // Defer non-critical startup work to avoid thread pool contention.
       // The window is now visible and responsive; these run in the background.
@@ -1255,6 +1256,7 @@ function createWindow(): void {
       notificationManager.setMainWindow(null);
     }
     if (updaterService) {
+      updaterService.stopPeriodicCheck();
       updaterService.setMainWindow(null);
     }
     if (cliInstallerService) {
diff --git a/src/main/services/extensions/install/McpInstallService.ts b/src/main/services/extensions/install/McpInstallService.ts
index ec42a3aa..3c83c0fe 100644
--- a/src/main/services/extensions/install/McpInstallService.ts
+++ b/src/main/services/extensions/install/McpInstallService.ts
@@ -7,8 +7,12 @@
  * from renderer).
  */
 
+import { ClaudeBinaryResolver } from '@main/services/team/ClaudeBinaryResolver';
 import { execCli } from '@main/utils/childProcess';
+import { buildEnrichedEnv } from '@main/utils/cliEnv';
+import { CLI_NOT_FOUND_MESSAGE } from '@shared/constants/cli';
 import { createLogger } from '@shared/utils/logger';
+import path from 'path';
 
 import type { McpCatalogAggregator } from '../catalog/McpCatalogAggregator';
 import type {
@@ -34,10 +38,7 @@ const HEADER_KEY_RE = /^[A-Za-z][\w-]{0,100}$/;
 const TIMEOUT_MS = 30_000;
 
 export class McpInstallService {
-  constructor(
-    private readonly claudeBinary: string | null,
-    private readonly aggregator: McpCatalogAggregator
-  ) {}
+  constructor(private readonly aggregator: McpCatalogAggregator) {}
 
   async install(request: McpInstallRequest): Promise<OperationResult> {
     const { registryId, serverName, scope, projectPath, envValues, headers } = request;
@@ -79,7 +80,7 @@ export class McpInstallService {
     }
 
     // 5. Validate projectPath (if provided, must be absolute)
-    if (projectPath && !projectPath.startsWith('/')) {
+    if (projectPath && !path.isAbsolute(projectPath)) {
       return {
         state: 'error',
         error: 'projectPath must be an absolute path',
@@ -161,9 +162,18 @@ export class McpInstallService {
     // Don't log env values or header values (may contain secrets)
 
     try {
-      const { stderr } = await execCli(this.claudeBinary, args, {
+      const claudeBinary = await ClaudeBinaryResolver.resolve();
+      if (!claudeBinary) {
+        return {
+          state: 'error',
+          error: CLI_NOT_FOUND_MESSAGE,
+        };
+      }
+
+      const { stderr } = await execCli(claudeBinary, args, {
         timeout: TIMEOUT_MS,
         cwd: projectPath,
+        env: buildEnrichedEnv(claudeBinary),
       });
 
       if (stderr) {
@@ -214,7 +224,7 @@ export class McpInstallService {
       }
     }
 
-    if (projectPath && !projectPath.startsWith('/')) {
+    if (projectPath && !path.isAbsolute(projectPath)) {
       return { state: 'error', error: 'projectPath must be an absolute path' };
     }
 
@@ -263,9 +273,18 @@ export class McpInstallService {
     );
 
     try {
-      const { stderr } = await execCli(this.claudeBinary, args, {
+      const claudeBinary = await ClaudeBinaryResolver.resolve();
+      if (!claudeBinary) {
+        return {
+          state: 'error',
+          error: CLI_NOT_FOUND_MESSAGE,
+        };
+      }
+
+      const { stderr } = await execCli(claudeBinary, args, {
         timeout: TIMEOUT_MS,
         cwd: projectPath,
+        env: buildEnrichedEnv(claudeBinary),
       });
 
       if (stderr) {
@@ -300,7 +319,7 @@ export class McpInstallService {
       };
     }
 
-    if (projectPath && !projectPath.startsWith('/')) {
+    if (projectPath && !path.isAbsolute(projectPath)) {
       return {
         state: 'error',
         error: 'projectPath must be an absolute path',
@@ -316,9 +335,18 @@ export class McpInstallService {
     logger.info(`Removing MCP server: ${name} (scope: ${scope ?? 'local'})`);
 
     try {
-      await execCli(this.claudeBinary, args, {
+      const claudeBinary = await ClaudeBinaryResolver.resolve();
+      if (!claudeBinary) {
+        return {
+          state: 'error',
+          error: CLI_NOT_FOUND_MESSAGE,
+        };
+      }
+
+      await execCli(claudeBinary, args, {
         timeout: TIMEOUT_MS,
         cwd: projectPath,
+        env: buildEnrichedEnv(claudeBinary),
       });
       return { state: 'success' };
     } catch (err) {
diff --git a/src/main/services/extensions/install/PluginInstallService.ts b/src/main/services/extensions/install/PluginInstallService.ts
index d81f24b4..f3f91d74 100644
--- a/src/main/services/extensions/install/PluginInstallService.ts
+++ b/src/main/services/extensions/install/PluginInstallService.ts
@@ -5,8 +5,12 @@
  * from the current catalog snapshot (never trusts renderer-provided paths).
  */
 
+import { ClaudeBinaryResolver } from '@main/services/team/ClaudeBinaryResolver';
 import { execCli } from '@main/utils/childProcess';
+import { buildEnrichedEnv } from '@main/utils/cliEnv';
+import { CLI_NOT_FOUND_MESSAGE } from '@shared/constants/cli';
 import { createLogger } from '@shared/utils/logger';
+import path from 'path';
 
 import type { PluginCatalogService } from '../catalog/PluginCatalogService';
 import type { OperationResult, PluginInstallRequest } from '@shared/types/extensions';
@@ -23,10 +27,7 @@ const INSTALL_TIMEOUT_MS = 120_000; // plugins may clone repos
 const UNINSTALL_TIMEOUT_MS = 30_000;
 
 export class PluginInstallService {
-  constructor(
-    private readonly claudeBinary: string | null,
-    private readonly catalogService: PluginCatalogService
-  ) {}
+  constructor(private readonly catalogService: PluginCatalogService) {}
 
   async install(request: PluginInstallRequest): Promise<OperationResult> {
     const { pluginId, scope, projectPath } = request;
@@ -40,7 +41,7 @@ export class PluginInstallService {
     }
 
     // 2. Validate projectPath
-    if (projectPath && !projectPath.startsWith('/')) {
+    if (projectPath && !path.isAbsolute(projectPath)) {
       return {
         state: 'error',
         error: 'projectPath must be an absolute path',
@@ -76,9 +77,18 @@ export class PluginInstallService {
     logger.info(`Installing plugin: ${qualifiedName} (scope: ${scope ?? 'user'})`);
 
     try {
-      const { stdout, stderr } = await execCli(this.claudeBinary, args, {
+      const claudeBinary = await ClaudeBinaryResolver.resolve();
+      if (!claudeBinary) {
+        return {
+          state: 'error',
+          error: CLI_NOT_FOUND_MESSAGE,
+        };
+      }
+
+      const { stdout, stderr } = await execCli(claudeBinary, args, {
         timeout: INSTALL_TIMEOUT_MS,
         cwd: projectPath,
+        env: buildEnrichedEnv(claudeBinary),
       });
 
       if (stderr && !stdout) {
@@ -106,7 +116,7 @@ export class PluginInstallService {
       };
     }
 
-    if (projectPath && !projectPath.startsWith('/')) {
+    if (projectPath && !path.isAbsolute(projectPath)) {
       return {
         state: 'error',
         error: 'projectPath must be an absolute path',
@@ -140,9 +150,18 @@ export class PluginInstallService {
     logger.info(`Uninstalling plugin: ${qualifiedName} (scope: ${scope ?? 'user'})`);
 
     try {
-      await execCli(this.claudeBinary, args, {
+      const claudeBinary = await ClaudeBinaryResolver.resolve();
+      if (!claudeBinary) {
+        return {
+          state: 'error',
+          error: CLI_NOT_FOUND_MESSAGE,
+        };
+      }
+
+      await execCli(claudeBinary, args, {
         timeout: UNINSTALL_TIMEOUT_MS,
         cwd: projectPath,
+        env: buildEnrichedEnv(claudeBinary),
       });
       return { state: 'success' };
     } catch (err) {
diff --git a/src/main/services/extensions/state/McpHealthDiagnosticsService.ts b/src/main/services/extensions/state/McpHealthDiagnosticsService.ts
index 2f6e0f47..1000adc9 100644
--- a/src/main/services/extensions/state/McpHealthDiagnosticsService.ts
+++ b/src/main/services/extensions/state/McpHealthDiagnosticsService.ts
@@ -2,7 +2,10 @@
  * Runs `claude mcp list` and parses per-server health statuses.
  */
 
+import { ClaudeBinaryResolver } from '@main/services/team/ClaudeBinaryResolver';
 import { execCli } from '@main/utils/childProcess';
+import { buildEnrichedEnv } from '@main/utils/cliEnv';
+import { CLI_NOT_FOUND_MESSAGE } from '@shared/constants/cli';
 import { createLogger } from '@shared/utils/logger';
 
 import type { McpServerDiagnostic, McpServerHealthStatus } from '@shared/types/extensions';
@@ -12,11 +15,15 @@ const logger = createLogger('Extensions:McpHealthDiagnostics');
 const TIMEOUT_MS = 30_000;
 
 export class McpHealthDiagnosticsService {
-  constructor(private readonly claudeBinary: string | null) {}
-
   async diagnose(): Promise<McpServerDiagnostic[]> {
-    const { stdout, stderr } = await execCli(this.claudeBinary, ['mcp', 'list'], {
+    const claudeBinary = await ClaudeBinaryResolver.resolve();
+    if (!claudeBinary) {
+      throw new Error(CLI_NOT_FOUND_MESSAGE);
+    }
+
+    const { stdout, stderr } = await execCli(claudeBinary, ['mcp', 'list'], {
       timeout: TIMEOUT_MS,
+      env: buildEnrichedEnv(claudeBinary),
     });
 
     const output = [stdout, stderr].filter(Boolean).join('\n');
diff --git a/src/main/services/team/ClaudeBinaryResolver.ts b/src/main/services/team/ClaudeBinaryResolver.ts
index 7df3f062..644354cf 100644
--- a/src/main/services/team/ClaudeBinaryResolver.ts
+++ b/src/main/services/team/ClaudeBinaryResolver.ts
@@ -167,6 +167,12 @@ async function resolveFromExplicitPath(inputPath: string): Promise<string | null
 
 let cachedPath: string | null | undefined;
 
+/** Timestamp of last successful cache verification (ms). */
+let cacheVerifiedAt = 0;
+
+/** Re-verify cached binary at most once per 30 seconds. */
+const CACHE_VERIFY_TTL_MS = 30_000;
+
 /** Coalesce concurrent first resolves so `cachedPath` is not torn by parallel scans. */
 let resolveInFlight: Promise<string | null> | null = null;
 
@@ -177,10 +183,25 @@ export class ClaudeBinaryResolver {
    */
   static clearCache(): void {
     cachedPath = undefined;
+    cacheVerifiedAt = 0;
   }
 
   static async resolve(): Promise<string | null> {
-    if (cachedPath !== undefined) return cachedPath;
+    if (cachedPath !== undefined) {
+      const now = Date.now();
+      // Re-verify the cached binary still exists, but at most once per TTL
+      if (cachedPath !== null && now - cacheVerifiedAt > CACHE_VERIFY_TTL_MS) {
+        if (await isExecutable(cachedPath)) {
+          cacheVerifiedAt = now;
+          return cachedPath;
+        }
+        cachedPath = undefined;
+        cacheVerifiedAt = 0;
+        // Fall through to full resolution below
+      } else {
+        return cachedPath;
+      }
+    }
     if (!resolveInFlight) {
       resolveInFlight = ClaudeBinaryResolver.runResolve().finally(() => {
         resolveInFlight = null;
@@ -203,6 +224,7 @@ export class ClaudeBinaryResolver {
 
       if (resolvedOverride) {
         cachedPath = resolvedOverride;
+        cacheVerifiedAt = Date.now();
         return cachedPath;
       }
     }
@@ -211,6 +233,7 @@ export class ClaudeBinaryResolver {
     const fromPath = await resolveFromPathEnv(baseBinaryName, enrichedPath);
     if (fromPath) {
       cachedPath = fromPath;
+      cacheVerifiedAt = Date.now();
       return cachedPath;
     }
 
@@ -259,6 +282,7 @@ export class ClaudeBinaryResolver {
     const found = results.find((r) => r.ok);
     if (found) {
       cachedPath = found.path;
+      cacheVerifiedAt = Date.now();
       return cachedPath;
     }
 
diff --git a/src/main/utils/childProcess.ts b/src/main/utils/childProcess.ts
index 02165f84..82ca5118 100644
--- a/src/main/utils/childProcess.ts
+++ b/src/main/utils/childProcess.ts
@@ -106,8 +106,7 @@ function withCliEnv<T extends { env?: NodeJS.ProcessEnv | Record<string, string
 
 /**
  * Execute a CLI binary, falling back to running the command through a
- * shell on Windows if the normal path-based spawn fails.  `binaryPath`
- * may be `null` which causes `claude` (lookup via PATH) to be used.
+ * shell on Windows if the normal path-based spawn fails.
  *
  * The return value matches the shape of Node's `execFile` promise: an
  * object with `stdout` and `stderr` strings.
@@ -117,7 +116,12 @@ export async function execCli(
   args: string[],
   options: ExecFileOptions = {}
 ): Promise<{ stdout: string; stderr: string }> {
-  const target = binaryPath || 'claude';
+  if (!binaryPath) {
+    throw new Error(
+      'Claude CLI binary path is null. Resolve the binary via ClaudeBinaryResolver before calling execCli.'
+    );
+  }
+  const target = binaryPath;
   const opts = withCliEnv(options);
 
   // attempt the normal execFile path first
diff --git a/src/main/utils/cliEnv.ts b/src/main/utils/cliEnv.ts
new file mode 100644
index 00000000..bf08528a
--- /dev/null
+++ b/src/main/utils/cliEnv.ts
@@ -0,0 +1,22 @@
+/**
+ * Builds an enriched environment for Claude CLI child processes.
+ *
+ * Packaged Electron apps on macOS receive a minimal PATH (often just /usr/bin:/bin).
+ * This helper merges the user's interactive-shell env (cached during startup) with
+ * common install locations so that `claude` and its subprocesses (node, npx, etc.)
+ * can find the tools they need.
+ */
+
+import { buildMergedCliPath } from '@main/utils/cliPathMerge';
+import { getCachedShellEnv, getShellPreferredHome } from '@main/utils/shellEnv';
+
+export function buildEnrichedEnv(binaryPath?: string | null): NodeJS.ProcessEnv {
+  const home = getShellPreferredHome();
+  return {
+    ...process.env,
+    ...(getCachedShellEnv() ?? {}),
+    HOME: home,
+    USERPROFILE: home,
+    PATH: buildMergedCliPath(binaryPath),
+  };
+}
diff --git a/src/renderer/components/extensions/mcp/McpServersPanel.tsx b/src/renderer/components/extensions/mcp/McpServersPanel.tsx
index e17e8335..136713cc 100644
--- a/src/renderer/components/extensions/mcp/McpServersPanel.tsx
+++ b/src/renderer/components/extensions/mcp/McpServersPanel.tsx
@@ -15,6 +15,7 @@ import {
 } from '@renderer/components/ui/select';
 import { useStore } from '@renderer/store';
 import { formatRelativeTime } from '@renderer/utils/formatters';
+import { CLI_NOT_FOUND_MARKER } from '@shared/constants/cli';
 import { sanitizeMcpServerName } from '@shared/utils/extensionNormalizers';
 import { AlertTriangle, RefreshCw, Search, Server } from 'lucide-react';
 
@@ -311,11 +312,23 @@ export const McpServersPanel = ({
         </div>
       )}
 
-      {mcpDiagnosticsError && (
-        <div className="rounded-md border border-red-500/30 bg-red-500/5 p-4 text-sm text-red-400">
-          {mcpDiagnosticsError}
-        </div>
-      )}
+      {mcpDiagnosticsError &&
+        (mcpDiagnosticsError.includes(CLI_NOT_FOUND_MARKER) ? (
+          <div className="flex items-start gap-3 rounded-md border border-amber-500/30 bg-amber-500/5 px-4 py-3">
+            <AlertTriangle className="mt-0.5 size-4 shrink-0 text-amber-400" />
+            <div>
+              <p className="text-sm font-medium text-amber-300">Claude CLI not installed</p>
+              <p className="mt-0.5 text-xs text-text-muted">
+                MCP health checks require Claude CLI. Go to the Dashboard to install it
+                automatically.
+              </p>
+            </div>
+          </div>
+        ) : (
+          <div className="rounded-md border border-red-500/30 bg-red-500/5 p-4 text-sm text-red-400">
+            {mcpDiagnosticsError}
+          </div>
+        ))}
 
       {/* Empty state */}
       {!isLoading && displayServers.length === 0 && (
diff --git a/src/shared/constants/cli.ts b/src/shared/constants/cli.ts
new file mode 100644
index 00000000..b0789a50
--- /dev/null
+++ b/src/shared/constants/cli.ts
@@ -0,0 +1,15 @@
+/**
+ * CLI error message marker.
+ *
+ * All "CLI not found" error messages across main process services MUST
+ * include this substring so the renderer can detect CLI-missing state
+ * without relying on brittle string matching against the full message.
+ */
+export const CLI_NOT_FOUND_MARKER = 'CLI not found';
+
+/**
+ * User-facing message when CLI binary cannot be resolved.
+ * Contains CLI_NOT_FOUND_MARKER so the renderer can detect it.
+ */
+export const CLI_NOT_FOUND_MESSAGE =
+  'Claude CLI not found. Go to the Dashboard to install it automatically.';
diff --git a/src/shared/constants/index.ts b/src/shared/constants/index.ts
index 75122750..0cfa18c1 100644
--- a/src/shared/constants/index.ts
+++ b/src/shared/constants/index.ts
@@ -4,6 +4,7 @@
 
 export * from './agentBlocks';
 export * from './cache';
+export * from './cli';
 export * from './crossTeam';
 export * from './kanban';
 export * from './memberColors';
diff --git a/test/main/services/extensions/McpInstallService.test.ts b/test/main/services/extensions/McpInstallService.test.ts
index 1e4f79e6..40f1dc5a 100644
--- a/test/main/services/extensions/McpInstallService.test.ts
+++ b/test/main/services/extensions/McpInstallService.test.ts
@@ -11,6 +11,14 @@ vi.mock('@main/utils/childProcess', () => ({
   execCli: vi.fn(),
 }));
 
+vi.mock('@main/services/team/ClaudeBinaryResolver', () => ({
+  ClaudeBinaryResolver: {
+    resolve: vi.fn().mockResolvedValue('/usr/local/bin/claude'),
+  },
+}));
+
+import { ClaudeBinaryResolver } from '@main/services/team/ClaudeBinaryResolver';
+
 import { execCli } from '@main/utils/childProcess';
 
 const mockExecCli = vi.mocked(execCli);
@@ -67,8 +75,9 @@ describe('McpInstallService', () => {
 
   beforeEach(() => {
     vi.clearAllMocks();
+    vi.mocked(ClaudeBinaryResolver.resolve).mockResolvedValue('/usr/local/bin/claude');
     aggregator = createMockAggregator();
-    service = new McpInstallService(null, aggregator);
+    service = new McpInstallService(aggregator);
   });
 
   afterEach(() => {
@@ -91,7 +100,7 @@ describe('McpInstallService', () => {
 
       expect(result.state).toBe('success');
       expect(mockExecCli).toHaveBeenCalledWith(
-        null,
+        '/usr/local/bin/claude',
         ['mcp', 'add', '-s', 'user', '-e', 'UPSTASH_API_KEY=test-key-123', 'context7', '--', 'npx', '-y', '@upstash/context7-mcp@1.0.0'],
         expect.objectContaining({ timeout: 30_000 }),
       );
@@ -135,7 +144,7 @@ describe('McpInstallService', () => {
   describe('install (http)', () => {
     it('builds correct CLI args for HTTP server', async () => {
       aggregator = createMockAggregator(makeHttpServer());
-      service = new McpInstallService(null, aggregator);
+      service = new McpInstallService(aggregator);
       mockExecCli.mockResolvedValue({ stdout: '', stderr: '' });
 
       const result = await service.install({
@@ -148,7 +157,7 @@ describe('McpInstallService', () => {
 
       expect(result.state).toBe('success');
       expect(mockExecCli).toHaveBeenCalledWith(
-        null,
+        '/usr/local/bin/claude',
         ['mcp', 'add', '-s', 'user', '-t', 'sse', '-H', 'Authorization: Bearer token123', 'example-http', 'https://mcp.example.com/sse'],
         expect.objectContaining({ timeout: 30_000 }),
       );
@@ -174,7 +183,7 @@ describe('McpInstallService', () => {
 
     it('returns error if server not found in registry', async () => {
       aggregator = createMockAggregator(null);
-      service = new McpInstallService(null, aggregator);
+      service = new McpInstallService(aggregator);
 
       const result = await service.install({
         registryId: 'nonexistent',
@@ -194,7 +203,7 @@ describe('McpInstallService', () => {
         installSpec: null,
       };
       aggregator = createMockAggregator(serverNoSpec);
-      service = new McpInstallService(null, aggregator);
+      service = new McpInstallService(aggregator);
 
       const result = await service.install({
         registryId: 'test',
@@ -232,7 +241,7 @@ describe('McpInstallService', () => {
 
     it('masks header values in error messages', async () => {
       aggregator = createMockAggregator(makeHttpServer());
-      service = new McpInstallService(null, aggregator);
+      service = new McpInstallService(aggregator);
       mockExecCli.mockRejectedValue(
         new Error('Auth failed with Bearer my-token-value'),
       );
@@ -260,7 +269,7 @@ describe('McpInstallService', () => {
 
       expect(result.state).toBe('success');
       expect(mockExecCli).toHaveBeenCalledWith(
-        null,
+        '/usr/local/bin/claude',
         ['mcp', 'remove', 'context7'],
         expect.objectContaining({ timeout: 30_000 }),
       );
diff --git a/test/main/services/extensions/PluginInstallService.test.ts b/test/main/services/extensions/PluginInstallService.test.ts
index 4936527a..6e8f625e 100644
--- a/test/main/services/extensions/PluginInstallService.test.ts
+++ b/test/main/services/extensions/PluginInstallService.test.ts
@@ -10,6 +10,14 @@ vi.mock('@main/utils/childProcess', () => ({
   execCli: vi.fn(),
 }));
 
+vi.mock('@main/services/team/ClaudeBinaryResolver', () => ({
+  ClaudeBinaryResolver: {
+    resolve: vi.fn().mockResolvedValue('/usr/local/bin/claude'),
+  },
+}));
+
+import { ClaudeBinaryResolver } from '@main/services/team/ClaudeBinaryResolver';
+
 import { execCli } from '@main/utils/childProcess';
 
 const mockExecCli = vi.mocked(execCli);
@@ -33,8 +41,9 @@ describe('PluginInstallService', () => {
 
   beforeEach(() => {
     vi.clearAllMocks();
+    vi.mocked(ClaudeBinaryResolver.resolve).mockResolvedValue('/usr/local/bin/claude');
     catalog = createMockCatalog();
-    service = new PluginInstallService(null, catalog);
+    service = new PluginInstallService(catalog);
   });
 
   afterEach(() => {
@@ -54,7 +63,7 @@ describe('PluginInstallService', () => {
 
       expect(result.state).toBe('success');
       expect(mockExecCli).toHaveBeenCalledWith(
-        null,
+        '/usr/local/bin/claude',
         ['plugin', 'install', 'context7@claude-plugins-official'],
         expect.objectContaining({ timeout: 120_000 }),
       );
@@ -70,7 +79,7 @@ describe('PluginInstallService', () => {
       });
 
       expect(mockExecCli).toHaveBeenCalledWith(
-        null,
+        '/usr/local/bin/claude',
         ['plugin', 'install', '-s', 'project', 'context7@claude-plugins-official'],
         expect.objectContaining({ cwd: '/tmp/test-project' }),
       );
@@ -80,7 +89,7 @@ describe('PluginInstallService', () => {
       catalog = createMockCatalog({
         resolvePlugin: vi.fn().mockResolvedValue(null) as PluginCatalogService['resolvePlugin'],
       });
-      service = new PluginInstallService(null, catalog);
+      service = new PluginInstallService(catalog);
 
       const result = await service.install({ pluginId: 'nonexistent', scope: 'user' });
 
@@ -95,7 +104,7 @@ describe('PluginInstallService', () => {
           qualifiedName: '../../../etc/passwd',
         }) as PluginCatalogService['resolvePlugin'],
       });
-      service = new PluginInstallService(null, catalog);
+      service = new PluginInstallService(catalog);
 
       const result = await service.install({ pluginId: 'evil', scope: 'user' });
 
@@ -124,7 +133,7 @@ describe('PluginInstallService', () => {
 
       expect(result.state).toBe('success');
       expect(mockExecCli).toHaveBeenCalledWith(
-        null,
+        '/usr/local/bin/claude',
         ['plugin', 'uninstall', 'context7@claude-plugins-official'],
         expect.objectContaining({ timeout: 30_000 }),
       );
@@ -136,7 +145,7 @@ describe('PluginInstallService', () => {
       await service.uninstall('context7', 'project', '/tmp/test-project');
 
       expect(mockExecCli).toHaveBeenCalledWith(
-        null,
+        '/usr/local/bin/claude',
         ['plugin', 'uninstall', '-s', 'project', 'context7@claude-plugins-official'],
         expect.objectContaining({ cwd: '/tmp/test-project' }),
       );
@@ -146,7 +155,7 @@ describe('PluginInstallService', () => {
       catalog = createMockCatalog({
         resolvePlugin: vi.fn().mockResolvedValue(null) as PluginCatalogService['resolvePlugin'],
       });
-      service = new PluginInstallService(null, catalog);
+      service = new PluginInstallService(catalog);
 
       const result = await service.uninstall('nonexistent');