Improve error boundary granularity with page and section level boundaries

Implement three-level error boundary strategy:
- Top-level (app shell): catches critical failures
- Page-level: preserves navigation when page crashes
- Section-level: graceful degradation for charts/tables

Create new components:
- PageErrorBoundary: wraps page routes
- SectionErrorBoundary: wraps data-heavy sections

Enhance ErrorBoundary with customizable titles, messages, and reload behavior.

Apply page boundaries to all route handlers in App.tsx.

Apply section boundaries to:
- DashboardPage: server status, ban trend, country charts, ban list
- JailsPage: jail overview, ban/unban form, IP lookup
- MapPage: world map, ban table
- ConfigPage: configuration editor
- HistoryPage: history table, IP detail view
- BlocklistsPage: sources, schedule, import log

Update Web-Development.md with error boundary strategy documentation.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

frontend/src/pages/ConfigPage.tsx

@@ -10,9 +10,13 @@
  *   Actions      — structured action.d form editor
  *   Server       — server-level settings, map thresholds, service health + log viewer
  *   Regex Tester — live pattern tester
+ *
+ * Configuration content is wrapped with SectionErrorBoundary to prevent
+ * one tab or editor from crashing the entire page.
  */
 
 import { Text, makeStyles, tokens } from "@fluentui/react-components";
+import { SectionErrorBoundary } from "../components/SectionErrorBoundary";
 import { ConfigPageContainer } from "../components/config/ConfigPageContainer";
 
 const useStyles = makeStyles({
@@ -44,7 +48,9 @@ export function ConfigPage(): React.JSX.Element {
         </Text>
       </div>
 
-      <ConfigPageContainer />
+      <SectionErrorBoundary sectionName="Configuration Editor">
+        <ConfigPageContainer />
+      </SectionErrorBoundary>
     </div>
   );
 }