Normalize screen layouts: extract control groups, unify sidebar widths, and refactor PromptsScreen

- Extract ToolControls group from ToolsScreen (search, list, list-changed indicator)
- Extract PromptControls and PromptListItem groups for PromptsScreen sidebar
- Refactor PromptsScreen to sidebar + detail layout (matching ResourcesScreen pattern)
- Refactor PromptArgumentsForm to accept a single prompt instead of a dropdown
- Normalize all screen sidebar widths to 340px (Tools, Resources, Prompts, Logs, Tasks, History)
- Convert ToolsScreen from Grid-only to sidebar + Grid layout
- Replace LogControls checkboxes with full-width toggle buttons
- Move Clear/Export buttons from LogControls to LogStreamPanel toolbar
- Make PromptArgumentsForm "Get Prompt" button right-aligned and compact
- Update all affected stories and ConnectedView

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

clients/web/src/components/groups/PromptListItem/PromptListItem.stories.tsx

@@ -0,0 +1,37 @@
+import type { Meta, StoryObj } from "@storybook/react-vite";
+import { fn } from "storybook/test";
+import { PromptListItem } from "./PromptListItem";
+
+const meta: Meta<typeof PromptListItem> = {
+  title: "Groups/PromptListItem",
+  component: PromptListItem,
+  args: {
+    onClick: fn(),
+  },
+};
+
+export default meta;
+type Story = StoryObj<typeof PromptListItem>;
+
+export const Default: Story = {
+  args: {
+    name: "summarize",
+    description: "Summarize the given text into key points",
+    selected: false,
+  },
+};
+
+export const Selected: Story = {
+  args: {
+    name: "translate",
+    description: "Translate text from one language to another",
+    selected: true,
+  },
+};
+
+export const NoDescription: Story = {
+  args: {
+    name: "code-review",
+    selected: false,
+  },
+};

clients/web/src/components/groups/PromptListItem/PromptListItem.tsx

@@ -0,0 +1,40 @@
+import { Stack, Text, UnstyledButton } from "@mantine/core";
+
+export interface PromptListItemProps {
+  name: string;
+  description?: string;
+  selected: boolean;
+  onClick: () => void;
+}
+
+const NameText = Text.withProps({
+  fw: 500,
+});
+
+const DescriptionText = Text.withProps({
+  size: "xs",
+  c: "dimmed",
+  lineClamp: 1,
+});
+
+export function PromptListItem({
+  name,
+  description,
+  selected,
+  onClick,
+}: PromptListItemProps) {
+  return (
+    <UnstyledButton
+      w="100%"
+      p="sm"
+      variant="listItem"
+      bg={selected ? "var(--mantine-primary-color-light)" : undefined}
+      onClick={onClick}
+    >
+      <Stack gap={2}>
+        <NameText>{name}</NameText>
+        {description && <DescriptionText>{description}</DescriptionText>}
+      </Stack>
+    </UnstyledButton>
+  );
+}