feat(frontend): polish styling, spacing, and add e2e integration tests for Phase 1.3

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

frontend/src/App.tsx

@@ -32,11 +32,11 @@ const AppContent: React.FC = () => {
   }
 
   return (
-    <div className="h-screen grid grid-rows-[1fr_auto] grid-cols-2">
-      <div className="border-r border-b border-gray-200 p-4">
+    <div className="h-screen grid grid-rows-[1fr_auto] grid-cols-2 bg-gray-50">
+      <div className="border-r border-b border-gray-200 p-4 min-h-0">
         <VideoPlaceholder />
       </div>
-      <div className="border-b border-gray-200 p-4 flex flex-col gap-4 overflow-y-auto">
+      <div className="border-b border-gray-200 p-6 flex flex-col gap-4 overflow-y-auto min-h-0">
         <QueryInput onSubmit={handleQuerySubmit} isLoading={queryMutation.isPending} />
         <KeywordsDisplay keywords={queryMutation.data?.keywords} isLoading={queryMutation.isPending} />
         <IngestPanel
@@ -46,7 +46,7 @@ const AppContent: React.FC = () => {
           error={ingestMutation.isError ? (ingestMutation.error instanceof Error ? ingestMutation.error.message : 'Upload failed') : null}
         />
       </div>
-      <div className="col-span-2 p-4 border-t border-gray-200 overflow-y-auto">
+      <div className="col-span-2 p-6 border-t border-gray-200 overflow-y-auto min-h-0">
         <ResponsePanel
           answer={queryMutation.data?.answer ?? null}
           sources={queryMutation.data?.sources ?? []}

frontend/src/components/KeywordsDisplay.tsx

@@ -28,7 +28,7 @@ export const KeywordsDisplay: React.FC<KeywordsDisplayProps> = ({ keywords, isLo
   }
 
   return (
-    <div className="space-y-2">
+    <div data-testid="keywords-section" className="space-y-2 transition-all duration-300 ease-in-out">
       <span className="text-xs text-gray-500 uppercase tracking-wide">Extracted Keywords:</span>
       <div data-testid="keywords-container" className="flex flex-wrap">
         {keywords?.map((keyword, index) => (

frontend/src/components/QueryInput.tsx

@@ -40,9 +40,9 @@ export const QueryInput: React.FC<QueryInputProps> = ({ onSubmit, isLoading }) =
       <button
         type="submit"
         disabled={isDisabled}
-        className="px-4 py-2 bg-blue-600 text-white font-medium rounded hover:bg-blue-700 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2 disabled:opacity-50 disabled:cursor-not-allowed disabled:hover:bg-blue-600"
+        className="px-4 py-2 bg-blue-600 text-white font-medium rounded hover:bg-blue-700 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2 disabled:opacity-50 disabled:cursor-not-allowed disabled:hover:bg-blue-600 transition-all duration-200"
       >
-        {isLoading ? 'Loading...' : 'Submit'}
+        {isLoading ? 'Processing...' : 'Submit'}
       </button>
     </form>
   )

frontend/src/test/components/KeywordsDisplay.test.tsx

@@ -55,8 +55,19 @@ describe('KeywordsDisplay', () => {
     const keywords = ['keyword1', 'keyword2', 'keyword3']
     render(<KeywordsDisplay keywords={keywords} isLoading={false} />)
     
-    const container = screen.getByTestId('keywords-container')
-    expect(container).toHaveClass('flex', 'flex-wrap')
+    const container = screen.getByTestId('keywords-section')
+    expect(container).toBeInTheDocument()
+    
+    const innerContainer = screen.getByTestId('keywords-container')
+    expect(innerContainer).toHaveClass('flex', 'flex-wrap')
+  })
+
+  it('has smooth transition classes on keywords section', () => {
+    const keywords = ['test']
+    render(<KeywordsDisplay keywords={keywords} isLoading={false} />)
+    
+    const section = screen.getByTestId('keywords-section')
+    expect(section).toHaveClass('transition-all', 'duration-300', 'ease-in-out')
   })
 
   it('renders each keyword chip with mr-2 mb-2 spacing', () => {

frontend/src/test/components/QueryInput.test.tsx

@@ -39,7 +39,7 @@ describe('QueryInput', () => {
 
   it('button is disabled when isLoading is true', () => {
     render(<QueryInput onSubmit={mockOnSubmit} isLoading={true} />)
-    const button = screen.getByRole('button', { name: /loading/i })
+    const button = screen.getByRole('button', { name: /processing/i })
     expect(button).toBeDisabled()
   })
 
@@ -52,7 +52,7 @@ describe('QueryInput', () => {
   it('button is disabled when isLoading is true even with text', () => {
     render(<QueryInput onSubmit={mockOnSubmit} isLoading={true} />)
     const textarea = screen.getByPlaceholderText('Ask a question about your documents...')
-    const button = screen.getByRole('button', { name: /loading/i })
+    const button = screen.getByRole('button', { name: /processing/i })
 
     fireEvent.change(textarea, { target: { value: 'Some question' } })
 

frontend/src/test/e2e/query_flow.test.tsx

@@ -0,0 +1,124 @@
+import React from 'react'
+import { render, screen, fireEvent, waitFor, act } from '@testing-library/react'
+import { queryClient } from '../../lib/queries'
+import App from '../../App'
+import type { QueryResponse, IngestResponse } from '../../types'
+
+vi.mock('../../lib/api', () => ({
+  queryDocument: vi.fn(),
+  ingestDocument: vi.fn(),
+}))
+
+import { queryDocument, ingestDocument } from '../../lib/api'
+
+const mockQueryDocument = vi.mocked(queryDocument)
+const mockIngestDocument = vi.mocked(ingestDocument)
+
+const mockQueryResponse: QueryResponse = {
+  keywords: ['legislative', 'council', 'meeting'],
+  answer: '- The meeting was held on January 15\n- Key topics were discussed',
+  sources: [
+    {
+      filename: 'minutes.pdf',
+      upload_date: '2024-01-15',
+      content_summary: 'Meeting minutes',
+      chunk_index: 0,
+    },
+  ],
+}
+
+const mockIngestResponse: IngestResponse = {
+  document_id: 'doc-abc123',
+  chunk_count: 5,
+  filename: 'test-document.pdf',
+}
+
+describe('Query flow integration (App-level)', () => {
+  beforeEach(() => {
+    queryClient.clear()
+    vi.restoreAllMocks()
+    mockQueryDocument.mockResolvedValue(mockQueryResponse)
+    mockIngestDocument.mockResolvedValue(mockIngestResponse)
+  })
+
+  it('shows empty state initially', () => {
+    render(<App />)
+
+    expect(screen.getByText(/Video upload coming in Phase 2/i)).toBeInTheDocument()
+    expect(
+      screen.getByText(/Ask a question to see the answer here/i),
+    ).toBeInTheDocument()
+
+    const submitButton = screen.getByRole('button', { name: /submit/i })
+    expect(submitButton).toBeDisabled()
+  })
+
+  it('full query flow: type question, submit, see keywords and answer', async () => {
+    mockQueryDocument.mockResolvedValue(mockQueryResponse)
+
+    render(<App />)
+
+    const textarea = screen.getByPlaceholderText(
+      'Ask a question about your documents...',
+    )
+    fireEvent.change(textarea, { target: { value: 'What happened at the meeting?' } })
+
+    const submitButton = screen.getByRole('button', { name: /submit/i })
+    await act(async () => {
+      fireEvent.click(submitButton)
+    })
+
+    await waitFor(() => {
+      expect(screen.getByText('legislative')).toBeInTheDocument()
+    })
+    expect(screen.getByText('council')).toBeInTheDocument()
+    expect(screen.getByText('meeting')).toBeInTheDocument()
+
+    await waitFor(() => {
+      expect(screen.getByText('The meeting was held on January 15')).toBeInTheDocument()
+    })
+    expect(screen.getByText('Key topics were discussed')).toBeInTheDocument()
+
+    expect(screen.getByText('minutes.pdf')).toBeInTheDocument()
+    expect(screen.getByText('Meeting minutes')).toBeInTheDocument()
+  })
+
+  it('handles API error gracefully', async () => {
+    mockQueryDocument.mockRejectedValue(new Error('Server error: 500'))
+
+    render(<App />)
+
+    const textarea = screen.getByPlaceholderText(
+      'Ask a question about your documents...',
+    )
+    fireEvent.change(textarea, { target: { value: 'Will this fail?' } })
+
+    const submitButton = screen.getByRole('button', { name: /submit/i })
+    await act(async () => {
+      fireEvent.click(submitButton)
+    })
+
+    await waitFor(() => {
+      expect(screen.getByText(/Server error: 500/i)).toBeInTheDocument()
+    })
+  })
+
+  it('handles ingest flow: upload document successfully', async () => {
+    mockIngestDocument.mockResolvedValue(mockIngestResponse)
+
+    render(<App />)
+
+    const fileInput = screen.getByTestId('file-input')
+    const file = new File(['dummy content'], 'test-document.pdf', {
+      type: 'application/pdf',
+    })
+
+    await act(async () => {
+      fireEvent.change(fileInput, { target: { files: [file] } })
+    })
+
+    await waitFor(() => {
+      expect(screen.getByText(/Uploaded test-document\.pdf/i)).toBeInTheDocument()
+    })
+  })
+})