remove: session operations center and progress panel

The bottom-right progress panel duplicated feedback already shown by
toasts. Remove it and the operation-tracking state to simplify the UI:

- Delete state/session-operations.tsx and session-progress-panel.tsx.
- Remove SessionOperationsProvider/SessionProgressPanel from AppShell.
- Remove startOperation/completeOperation calls from useInstanceActions
  and ToolStarter.
- Remove SessionOperationsProvider wrapper from DashboardPage.test.tsx.
- Remove .session-progress-panel CSS rules.
- Format use-events.test.ts mock to match project lint rules.

Quality gates: npm run typecheck, npm run lint, npm test -- --run
(87 passed).

apps/web/src/components/app-shell.tsx

@@ -8,10 +8,8 @@ import { useMobileViewport } from "../hooks/use-mobile-viewport";
 import { EventProvider } from "../state/events";
 import { ToastProvider } from "../state/toast";
 import { NotificationProvider } from "../state/notifications";
-import { SessionOperationsProvider } from "../state/session-operations";
 import { EventToastBridge } from "./features/notification/event-toast-bridge";
 import { NotificationCenter } from "./features/notification/notification-center";
-import { SessionProgressPanel } from "./features/session/session-progress-panel";
 import { Icon } from "./icon";
 import { MobileNav } from "./features/mobile/mobile-nav";
 import { StartToolFAB } from "./features/tool/start-tool-fab";
@@ -87,12 +85,10 @@ export const AppShell = () => {
 			<EventProvider>
 				<ToastProvider>
 					<NotificationProvider>
-						<SessionOperationsProvider>
-							<EventToastBridge />
-							<div className="shell mobile-terminal-shell">
-								<Outlet />
-							</div>
-						</SessionOperationsProvider>
+						<EventToastBridge />
+						<div className="shell mobile-terminal-shell">
+							<Outlet />
+						</div>
 					</NotificationProvider>
 				</ToastProvider>
 			</EventProvider>
@@ -103,10 +99,8 @@ export const AppShell = () => {
 		<EventProvider>
 			<ToastProvider>
 				<NotificationProvider>
-					<SessionOperationsProvider>
-						<EventToastBridge />
-						<SessionProgressPanel />
-						<div className="shell">
+					<EventToastBridge />
+					<div className="shell">
 							<header className="shell-header">
 								<Link className="brand" to="/">
 									Headquarter
@@ -180,7 +174,6 @@ export const AppShell = () => {
 							)}
 							<StartToolFAB />
 						</div>
-					</SessionOperationsProvider>
 				</NotificationProvider>
 			</ToastProvider>
 		</EventProvider>