refactor: unify layout widths and font sizes

- Add MAX_CONTENT_WIDTH (820px) constant for consistent chat/form widths
- Bump theme font sizes (base now 16px) for better readability
- Apply max width to stream view, input area, and new agent form
- Position new agent form at bottom of scroll area
- Remove working directory helper text
- Add cmd+b sidebar toggle when textarea is focused

packages/app/src/app/index.tsx

@@ -26,6 +26,7 @@ import { useDaemonConnections } from "@/contexts/daemon-connections-context";
 import { formatConnectionStatus } from "@/utils/daemons";
 import { useSessionStore } from "@/stores/session-store";
 import { generateMessageId } from "@/types/stream";
+import { MAX_CONTENT_WIDTH } from "@/constants/layout";
 import type {
   AgentProvider,
   AgentSessionConfig,
@@ -843,12 +844,16 @@ const styles = StyleSheet.create((theme) => ({
   },
   configScrollContent: {
     flexGrow: 1,
+    justifyContent: "flex-end",
   },
   configSection: {
     paddingHorizontal: theme.spacing[4],
     paddingTop: theme.spacing[3],
     paddingBottom: theme.spacing[4],
     gap: theme.spacing[2],
+    maxWidth: MAX_CONTENT_WIDTH,
+    alignSelf: "center",
+    width: "100%",
   },
   configRow: {
     flexDirection: "row",

packages/app/src/components/agent-form/agent-form-dropdowns.tsx

@@ -619,11 +619,6 @@ export function WorkingDirectoryDropdown({
         onPress={handleOpen}
         disabled={disabled}
         errorMessage={errorMessage || undefined}
-        helperText={
-          hasSuggestedPaths
-            ? "Search directories from existing agents or paste a new path."
-            : "No agent directories yet - search to add one."
-        }
         controlRef={anchorRef}
       />
       <AdaptiveSelect

packages/app/src/components/agent-input-area.tsx

@@ -16,7 +16,7 @@ import Animated, {
 import { useReanimatedKeyboardAnimation } from "react-native-keyboard-controller";
 import { useSafeAreaInsets } from "react-native-safe-area-context";
 import { useRealtime } from "@/contexts/realtime-context";
-import { FOOTER_HEIGHT } from "@/constants/layout";
+import { FOOTER_HEIGHT, MAX_CONTENT_WIDTH } from "@/constants/layout";
 import { generateMessageId } from "@/types/stream";
 import { AgentStatusBar } from "./agent-status-bar";
 import { RealtimeControls } from "./realtime-controls";
@@ -52,7 +52,6 @@ interface AgentInputAreaProps {
 }
 
 const EMPTY_ARRAY: readonly QueuedMessage[] = [];
-const MAX_INPUT_WIDTH = 960;
 // Android currently crashes inside ViewGroup.dispatchDraw when running Reanimated
 // entering/exiting animations (see react-native-reanimated#8422), so guard them.
 const SHOULD_DISABLE_ENTRY_EXIT_ANIMATIONS = Platform.OS === "android";
@@ -525,7 +524,7 @@ const styles = StyleSheet.create(((theme: Theme) => ({
   },
   inputAreaContent: {
     width: "100%",
-    maxWidth: MAX_INPUT_WIDTH,
+    maxWidth: MAX_CONTENT_WIDTH,
     gap: theme.spacing[3],
   },
   realtimeButton: {

packages/app/src/components/agent-stream-view.tsx

@@ -43,8 +43,7 @@ import {
 } from "@/utils/tool-call-parsers";
 import { ToolCallSheetProvider } from "./tool-call-sheet";
 import { createMarkdownStyles } from "@/styles/markdown-styles";
-
+import { MAX_CONTENT_WIDTH } from "@/constants/layout";
-const MAX_CHAT_WIDTH = 960;
 type PermissionResolvedMessage = Extract<
   SessionOutboundMessage,
   { type: "agent_permission_resolved" }
@@ -1024,7 +1023,7 @@ const stylesheet = StyleSheet.create((theme) => ({
   },
   contentWrapper: {
     width: "100%",
-    maxWidth: MAX_CHAT_WIDTH,
+    maxWidth: MAX_CONTENT_WIDTH,
     alignSelf: "center",
   },
   list: {
@@ -1033,7 +1032,7 @@ const stylesheet = StyleSheet.create((theme) => ({
   },
   streamItemWrapper: {
     width: "100%",
-    maxWidth: MAX_CHAT_WIDTH,
+    maxWidth: MAX_CONTENT_WIDTH,
     alignSelf: "center",
   },
   emptyState: {
@@ -1096,7 +1095,7 @@ const stylesheet = StyleSheet.create((theme) => ({
   },
   scrollToBottomInner: {
     width: "100%",
-    maxWidth: MAX_CHAT_WIDTH,
+    maxWidth: MAX_CONTENT_WIDTH,
     alignSelf: "center",
     alignItems: "center",
   },

packages/app/src/components/message-input.tsx

@@ -28,6 +28,7 @@ import { useDictation } from "@/hooks/use-dictation";
 import { DictationOverlay } from "./dictation-controls";
 import type { UseWebSocketReturn } from "@/hooks/use-websocket";
 import type { SessionContextValue } from "@/contexts/session-context";
+import { useSidebarStore } from "@/stores/sidebar-store";
 
 export interface ImageAttachment {
   uri: string;
@@ -113,6 +114,7 @@ export const MessageInput = forwardRef<MessageInputRef, MessageInputProps>(
     ref
   ) {
     const { theme } = useUnistyles();
+    const toggleSidebar = useSidebarStore((state) => state.toggle);
     const [inputHeight, setInputHeight] = useState(MIN_INPUT_HEIGHT);
     const textInputRef = useRef<
       TextInput | (TextInput & { getNativeRef?: () => unknown }) | null
@@ -383,6 +385,13 @@ export const MessageInput = forwardRef<MessageInputRef, MessageInputProps>(
     if (!shouldHandleDesktopSubmit) return;
     const { shiftKey, metaKey, ctrlKey } = event.nativeEvent;
 
+    // Cmd+B or Ctrl+B: toggle sidebar
+    if ((metaKey || ctrlKey) && event.nativeEvent.key === "b") {
+      event.preventDefault();
+      toggleSidebar();
+      return;
+    }
+
     // Cmd+D or Ctrl+D: start dictation or submit if already dictating
     if ((metaKey || ctrlKey) && event.nativeEvent.key === "d") {
       event.preventDefault();

packages/app/src/components/message.tsx

@@ -56,8 +56,8 @@ const userMessageStylesheet = StyleSheet.create((theme) => ({
   },
   text: {
     color: theme.colors.foreground,
-    fontSize: theme.fontSize.lg,
+    fontSize: theme.fontSize.base,
-    lineHeight: 24,
+    lineHeight: 22,
   },
   bubblePressed: {
     opacity: 0.85,

packages/app/src/constants/layout.ts

@@ -4,3 +4,6 @@ export const FOOTER_HEIGHT = 75;
 // Used by both agent header (ScreenHeader) and explorer sidebar header
 // This ensures both headers have the same visual height
 export const HEADER_INNER_HEIGHT = 48;
+
+// Max width for chat content (stream view, input area, new agent form)
+export const MAX_CONTENT_WIDTH = 820;

packages/app/src/styles/theme.ts

@@ -167,14 +167,14 @@ const commonTheme = {
   },
 
   fontSize: {
-    xs: 10,
+    xs: 12,
-    sm: 12,
+    sm: 14,
-    base: 14,
+    base: 16,
-    lg: 16,
+    lg: 18,
-    xl: 18,
+    xl: 20,
-    "2xl": 20,
+    "2xl": 22,
-    "3xl": 24,
+    "3xl": 26,
-    "4xl": 32,
+    "4xl": 34,
   },
 
   fontWeight: {