feat(estimates): add EstimatesPage hub with templates tab, estimate detail drawer, and template editor

- EstimatesPage: tabbed hub with Estimates and Templates tabs, KPI strip, search + filter
- EstimateDetailModal: right-side drawer showing scope of work, computed line items, and financial summary from template + roof area
- TemplateEditorModal: create/edit/duplicate templates with segmented mode toggle
- Owner-only template management (create, edit, duplicate, delete); Admin/FA read-only view
- Duplicate mode: toggle between 'Save as new copy' (default, editable name) and 'Replace original'
- MASTER_TEMPLATES and MOCK_ESTIMATES moved into mockStore with full CRUD helpers
- TemplateSelectionModal now reads from mockStore instead of local stub
- Sidebar nav updated to point to /estimates hub for all roles
- Routes added: /emp/fa/estimates, /admin/estimates, /owner/estimates

src/App.jsx

@@ -32,6 +32,7 @@ import SubContractorDashboard from './pages/subcontractor/SubContractorDashboard
 import CreateLeadPage from './pages/CreateLeadPage';
 import LeadsListPage from './pages/LeadsListPage';
 import LynkDispatchPage from './pages/LynkDispatchPage';
+import EstimatesPage from './pages/EstimatesPage';
 
 // ... (existing imports)
 const ProtectedRoute = ({ children, allowedRoles }) => {
@@ -101,6 +102,14 @@ function App() {
                 </ProtectedRoute>
               }
             />
+            <Route
+              path="/emp/fa/estimates"
+              element={
+                <ProtectedRoute allowedRoles={['FIELD_AGENT', 'ADMIN', 'OWNER']}>
+                  <EstimatesPage />
+                </ProtectedRoute>
+              }
+            />
             <Route
               path="/emp/fa/estimate"
               element={
@@ -166,6 +175,11 @@ function App() {
                 <ProCanvas />
               </ProtectedRoute>
             } />
+            <Route path="/owner/estimates" element={
+              <ProtectedRoute allowedRoles={['OWNER']}>
+                <EstimatesPage />
+              </ProtectedRoute>
+            } />
             <Route path="/owner/estimate" element={
               <ProtectedRoute allowedRoles={['OWNER']}>
                 <EstimateBuilder />
@@ -230,6 +244,14 @@ function App() {
                 </ProtectedRoute>
               }
             />
+            <Route
+              path="/admin/estimates"
+              element={
+                <ProtectedRoute allowedRoles={['ADMIN', 'OWNER']}>
+                  <EstimatesPage />
+                </ProtectedRoute>
+              }
+            />
             <Route
               path="/admin/estimate"
               element={