refactor(ui): name workspace surfaces

packages/ui/src/lib/router/index.ts

@@ -6,15 +6,15 @@
  *
  * URL Schema:
  * - `?session=<id>` - Navigate to specific session
- * - `?tab=<chat|git|diff|terminal|files>` - Active main tab
+ * - `?tab=<chat|git|diff|terminal|files>` - Legacy URL name for the active workspace surface
  * - `?settings=<section>` - Open settings to specific section
  * - `?file=<path>` - Diff view with file selected
  *
  * Examples:
  * - `/?session=abc123` - Open session abc123
- * - `/?tab=git` - Open git tab
+ * - `/?tab=git` - Open the Git surface
  * - `/?settings=providers` - Open settings to providers section
- * - `/?tab=diff&file=src/main.ts` - Open diff view with file
+ * - `/?tab=diff&file=src/main.ts` - Open the Diff surface with a file
  */
 
 export type { RouteState } from './types';

packages/ui/src/lib/router/parseRoute.ts

@@ -1,4 +1,4 @@
-import type { MainTab } from '@/stores/useUIStore';
+import type { WorkspaceSurface } from '@/stores/useUIStore';
 import {
   type RouteState,
   VALID_TABS,
@@ -52,13 +52,13 @@ function parseSessionId(params: URLSearchParams): string | null {
  * Parse main tab from URL parameters.
  * Returns null if missing or invalid.
  */
-function parseTab(params: URLSearchParams): MainTab | null {
+function parseTab(params: URLSearchParams): WorkspaceSurface | null {
   const value = params.get(ROUTE_PARAMS.TAB);
   if (!value) {
     return null;
   }
 
-  const normalized = value.toLowerCase().trim() as MainTab;
+  const normalized = value.toLowerCase().trim() as WorkspaceSurface;
   if (VALID_TABS.includes(normalized)) {
     return normalized;
   }

packages/ui/src/lib/router/serializeRoute.ts

@@ -1,4 +1,4 @@
-import type { MainTab } from '@/stores/useUIStore';
+import type { WorkspaceSurface } from '@/stores/useUIStore';
 import { isEmbeddedSessionChat } from '@/components/layout/contextPanelEmbeddedChat';
 import { ROUTE_PARAMS } from './types';
 
@@ -7,7 +7,7 @@ import { ROUTE_PARAMS } from './types';
  */
 export interface AppRouteState {
   sessionId: string | null;
-  tab: MainTab;
+  tab: WorkspaceSurface;
   isSettingsOpen: boolean;
   settingsPath: string;
   diffFile: string | null;
@@ -16,7 +16,7 @@ export interface AppRouteState {
 /**
  * Default tab when none is specified.
  */
-const DEFAULT_TAB: MainTab = 'chat';
+const DEFAULT_TAB: WorkspaceSurface = 'chat';
 
 /**
  * Serialize application state to URL search parameters.

packages/ui/src/lib/router/types.ts

@@ -1,5 +1,5 @@
 import type { SidebarSection } from '@/constants/sidebar';
-import type { MainTab } from '@/stores/useUIStore';
+import type { WorkspaceSurface } from '@/stores/useUIStore';
 
 /**
  * Represents the current route state derived from URL parameters.
@@ -8,8 +8,8 @@ import type { MainTab } from '@/stores/useUIStore';
 export interface RouteState {
   /** Session ID to navigate to */
   sessionId: string | null;
-  /** Main tab to display (chat, git, diff, terminal, files) */
-  tab: MainTab | null;
+  /** View selected through the legacy `tab` URL parameter. */
+  tab: WorkspaceSurface | null;
   /** Settings section - when non-null, settings dialog should be open */
   settingsPath: string | null;
   /** File path for diff view */
@@ -17,9 +17,9 @@ export interface RouteState {
 }
 
 /**
- * Valid main tab values for URL routing.
+ * Valid values for the legacy `tab` URL parameter.
  */
-export const VALID_TABS: readonly MainTab[] = ['chat', 'git', 'diff', 'terminal', 'files', 'diagram'] as const;
+export const VALID_TABS: readonly WorkspaceSurface[] = ['chat', 'git', 'diff', 'terminal', 'files', 'diagram'] as const;
 
 /**
  * Valid settings section values for URL routing.