feat(ai-assistant): show descriptive Noz hover tooltip on all entry points

Noz launched under early access and its three entry points (header button,
floating trigger, sidebar nav item) previously showed a bare "Noz" tooltip,
which does not educate users who don't yet recognize the name. Replace it with
a shared descriptive tooltip ("Noz, your AI teammate") sourced from a single
constant so the surfaces never drift.

- Add NOZ_TOOLTIP_TITLE in components/Noz/Noz.constants.ts
- Header button and floating trigger read the constant
- Add optional tooltip field to SidebarItem; NavItem wraps the whole row in a
  Tooltip (non-pinnable items only, to avoid nesting with the pin tooltip)
- Move the trigger's Noz icon to the Button prefix slot to match the codebase
  convention for icon-only buttons

frontend/src/components/HeaderRightSection/HeaderRightSection.tsx

@@ -4,6 +4,7 @@ import { Dot } from '@signozhq/icons';
 import { Button } from '@signozhq/ui/button';
 import { TooltipSimple } from '@signozhq/ui/tooltip';
 import Noz from 'components/Noz/Noz';
+import { NOZ_TOOLTIP_TITLE } from 'components/Noz/Noz.constants';
 import { Popover } from 'antd';
 import logEvent from 'api/common/logEvent';
 import { AIAssistantEvents } from 'container/AIAssistant/events';
@@ -109,7 +110,7 @@ function HeaderRightSection({
 						</span>
 					) : null}
 
-					<TooltipSimple title="Noz">
+					<TooltipSimple title={NOZ_TOOLTIP_TITLE}>
 						<Button
 							variant="solid"
 							color="secondary"

frontend/src/components/Noz/Noz.constants.ts

@@ -0,0 +1,2 @@
+/** Shared hover copy for every Noz entry point (header, floating trigger, sidebar). */
+export const NOZ_TOOLTIP_TITLE = 'Noz, your AI teammate';

frontend/src/container/AIAssistant/AIAssistantTrigger/AIAssistantTrigger.tsx

@@ -5,6 +5,7 @@ import { TooltipSimple } from '@signozhq/ui/tooltip';
 import logEvent from 'api/common/logEvent';
 import ROUTES from 'constants/routes';
 import Noz from 'components/Noz/Noz';
+import { NOZ_TOOLTIP_TITLE } from 'components/Noz/Noz.constants';
 
 import { AIAssistantEvents, AIAssistantOpenSource } from '../events';
 import { normalizePage } from '../hooks/useAIAssistantAnalyticsContext';
@@ -42,16 +43,15 @@ export default function AIAssistantTrigger(): JSX.Element | null {
 	}
 
 	return (
-		<TooltipSimple title="Noz">
+		<TooltipSimple title={NOZ_TOOLTIP_TITLE}>
 			<Button
 				variant="solid"
 				color="primary"
 				className={`${styles.trigger} noz-wave`}
 				onClick={handleOpen}
 				aria-label="Open Noz"
-			>
-				<Noz size={24} />
-			</Button>
+				prefix={<Noz size={24} />}
+			/>
 		</TooltipSimple>
 	);
 }

frontend/src/container/SideNav/NavItem/NavItem.tsx

@@ -5,7 +5,6 @@ import { Pin, PinOff } from '@signozhq/icons';
 
 import { SidebarItem } from '../sideNav.types';
 
-import './NavItem.styles.scss';
 import './NavItem.styles.scss';
 
 export default function NavItem({
@@ -27,7 +26,7 @@ export default function NavItem({
 	showIcon?: boolean;
 	dataTestId?: string;
 }): JSX.Element {
-	const { label, icon, isBeta, isNew, isEarlyAccess } = item;
+	const { label, icon, isBeta, isNew, isEarlyAccess, tooltip } = item;
 
 	const handleTogglePinClick = (
 		event: React.MouseEvent<SVGSVGElement, MouseEvent>,
@@ -36,7 +35,7 @@ export default function NavItem({
 		onTogglePin?.(item);
 	};
 
-	return (
+	const navItem = (
 		<div
 			className={cx(
 				'nav-item',
@@ -107,6 +106,15 @@ export default function NavItem({
 			</div>
 		</div>
 	);
+
+	// Only non-pinnable items set `tooltip`; it would nest with the pin tooltip.
+	return tooltip ? (
+		<Tooltip title={tooltip} placement="right">
+			{navItem}
+		</Tooltip>
+	) : (
+		navItem
+	);
 }
 
 NavItem.defaultProps = {

frontend/src/container/SideNav/menuItems.tsx

@@ -45,6 +45,7 @@ import {
 } from './sideNav.types';
 import { Style } from '@signozhq/design-tokens';
 import Noz from 'components/Noz/Noz';
+import { NOZ_TOOLTIP_TITLE } from 'components/Noz/Noz.constants';
 
 export const getStartedMenuItem = {
 	key: ROUTES.GET_STARTED,
@@ -97,6 +98,7 @@ export const aiAssistantMenuItem = {
 	icon: <Noz size={16} />,
 	itemKey: 'ai-assistant',
 	isEarlyAccess: true,
+	tooltip: NOZ_TOOLTIP_TITLE,
 };
 
 export const shortcutMenuItem = {

frontend/src/container/SideNav/sideNav.types.ts

@@ -15,6 +15,8 @@ export interface SidebarItem {
 	isBeta?: boolean;
 	isNew?: boolean;
 	isEarlyAccess?: boolean;
+	/** Hover copy for the whole item row (e.g. Noz's early-access tagline). */
+	tooltip?: ReactNode;
 	isPinned?: boolean;
 	children?: SidebarItem[];
 	isExternal?: boolean;