fix: valuation page Vietnamese diacritics, correct API routes, update tests

- Add proper Vietnamese diacritics to all valuation components
  (form, results, history) and their test assertions
- Fix valuation API client to use /analytics/valuation endpoint
- Return empty history gracefully (no server endpoint yet)

Co-Authored-By: Claude Opus 4 (1M context) <noreply@anthropic.com>

apps/web/components/valuation/__tests__/valuation-results.spec.tsx

@@ -43,7 +43,7 @@ const mockResult: ValuationResult = {
 describe('ValuationResults', () => {
   it('renders estimated price', () => {
     render(<ValuationResults result={mockResult} />);
-    expect(screen.getByText('5.00 ty VND')).toBeInTheDocument();
+    expect(screen.getByText('5.00 tỷ VNĐ')).toBeInTheDocument();
   });
 
   it('renders confidence percentage', () => {
@@ -53,17 +53,17 @@ describe('ValuationResults', () => {
 
   it('renders price per m2', () => {
     render(<ValuationResults result={mockResult} />);
-    expect(screen.getByText('62.5 tr/m2')).toBeInTheDocument();
+    expect(screen.getByText('62.5 tr/m²')).toBeInTheDocument();
   });
 
   it('renders price range', () => {
     render(<ValuationResults result={mockResult} />);
-    expect(screen.getByText(/4\.50 ty.*5\.50 ty/)).toBeInTheDocument();
+    expect(screen.getByText(/4\.50 tỷ.*5\.50 tỷ/)).toBeInTheDocument();
   });
 
   it('renders price drivers section', () => {
     render(<ValuationResults result={mockResult} />);
-    expect(screen.getByText('Yeu to anh huong gia')).toBeInTheDocument();
+    expect(screen.getByText('Yếu tố ảnh hưởng giá')).toBeInTheDocument();
     expect(screen.getByText('Vị trí trung tâm')).toBeInTheDocument();
     expect(screen.getByText('Tầng thấp')).toBeInTheDocument();
   });
@@ -80,31 +80,31 @@ describe('ValuationResults', () => {
 
   it('renders comparables section', () => {
     render(<ValuationResults result={mockResult} />);
-    expect(screen.getByText('Bat dong san tuong tu')).toBeInTheDocument();
+    expect(screen.getByText('Bất động sản tương tự')).toBeInTheDocument();
     expect(screen.getByText('Căn hộ tương tự A')).toBeInTheDocument();
     expect(screen.getByText('Căn hộ tương tự B')).toBeInTheDocument();
   });
 
   it('shows comparable count', () => {
     render(<ValuationResults result={mockResult} />);
-    expect(screen.getByText(/2 bat dong san/)).toBeInTheDocument();
+    expect(screen.getByText(/2 bất động sản/)).toBeInTheDocument();
   });
 
   it('shows similarity percentage for comparables', () => {
     render(<ValuationResults result={mockResult} />);
-    expect(screen.getByText('92% tuong tu')).toBeInTheDocument();
-    expect(screen.getByText('85% tuong tu')).toBeInTheDocument();
+    expect(screen.getByText('92% tương tự')).toBeInTheDocument();
+    expect(screen.getByText('85% tương tự')).toBeInTheDocument();
   });
 
   it('hides drivers section when empty', () => {
     const noDrivers = { ...mockResult, priceDrivers: [] };
     render(<ValuationResults result={noDrivers} />);
-    expect(screen.queryByText('Yeu to anh huong gia')).not.toBeInTheDocument();
+    expect(screen.queryByText('Yếu tố ảnh hưởng giá')).not.toBeInTheDocument();
   });
 
   it('hides comparables section when empty', () => {
     const noComps = { ...mockResult, comparables: [] };
     render(<ValuationResults result={noComps} />);
-    expect(screen.queryByText('Bat dong san tuong tu')).not.toBeInTheDocument();
+    expect(screen.queryByText('Bất động sản tương tự')).not.toBeInTheDocument();
   });
 });