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/MapPage.tsx

@@ -4,6 +4,8 @@
  * Shows a clickable SVG world map coloured by ban density, a time-range
  * selector, and a companion table filtered by the selected country (or all
  * bans when no country is selected).
+ *
+ * Critical sections wrapped with SectionErrorBoundary for resilience.
  */
 
 import { useState, useMemo, useEffect } from "react";
@@ -23,6 +25,7 @@ import {
   DismissRegular,
 } from "@fluentui/react-icons";
 import { DashboardFilterBar } from "../components/DashboardFilterBar";
+import { SectionErrorBoundary } from "../components/SectionErrorBoundary";
 import { WorldMap } from "../components/WorldMap";
 import { useMapData } from "../hooks/useMapData";
 import { useMapColorThresholds } from "../hooks/useMapColorThresholds";
@@ -250,15 +253,17 @@ export function MapPage(): React.JSX.Element {
       {/* immediate visual feedback before the filtered data arrives.       */}
       {/* ---------------------------------------------------------------- */}
       {!error && hasLoadedOnce && (
-        <WorldMap
-          countries={countries}
-          countryNames={countryNames}
-          selectedCountry={selectedCountry}
-          onSelectCountry={setSelectedCountry}
-          thresholdLow={thresholdLow}
-          thresholdMedium={thresholdMedium}
-          thresholdHigh={thresholdHigh}
-        />
+        <SectionErrorBoundary sectionName="World Map">
+          <WorldMap
+            countries={countries}
+            countryNames={countryNames}
+            selectedCountry={selectedCountry}
+            onSelectCountry={setSelectedCountry}
+            thresholdLow={thresholdLow}
+            thresholdMedium={thresholdMedium}
+            thresholdHigh={thresholdHigh}
+          />
+        </SectionErrorBoundary>
       )}
 
       {/* ---------------------------------------------------------------- */}
@@ -302,19 +307,21 @@ export function MapPage(): React.JSX.Element {
       {/* Companion bans table                                              */}
       {/* ---------------------------------------------------------------- */}
       {!error && hasLoadedOnce && (
-        <div className={mergeClasses(styles.tableWrapper, loading && styles.tableWrapperLoading)}>
-          <MapBansTable
-            pageBans={pageBans}
-            visibleCount={visibleBans.length}
-            page={page}
-            pageSize={pageSize}
-            totalPages={totalPages}
-            hasPrev={hasPrev}
-            hasNext={hasNext}
-            onPageChange={setPage}
-            onPageSizeChange={setPageSize}
-          />
-        </div>
+        <SectionErrorBoundary sectionName="Map Ban Table">
+          <div className={mergeClasses(styles.tableWrapper, loading && styles.tableWrapperLoading)}>
+            <MapBansTable
+              pageBans={pageBans}
+              visibleCount={visibleBans.length}
+              page={page}
+              pageSize={pageSize}
+              totalPages={totalPages}
+              hasPrev={hasPrev}
+              hasNext={hasNext}
+              onPageChange={setPage}
+              onPageSizeChange={setPageSize}
+            />
+          </div>
+        </SectionErrorBoundary>
       )}
     </div>
   );