Merge Map tab into Server tab and remove Map tab

The Map tab provided a form for editing world-map color thresholds
(low, medium, high). Moving this into the Server tab consolidates all
server-side configuration in one place.

- Add map color thresholds section to ServerTab with full validation
- Load map thresholds on component mount with useEffect
- Implement auto-save for threshold changes via useAutoSave hook
- Display threshold color interpolation guide
- Remove MapTab component import from ConfigPage
- Remove 'map' from TabValue type
- Remove Map tab element from TabList
- Remove conditional render for MapTab
- Remove MapTab from barrel export (index.ts)
- Delete MapTab.tsx file
- Update ConfigPage test to remove MapTab mock

All 123 frontend tests pass.

frontend/src/pages/ConfigPage.tsx

@@ -8,8 +8,7 @@
  *   Jails        — per-jail config accordion with inline editing
  *   Filters      — structured filter.d form editor
  *   Actions      — structured action.d form editor
- *   Server       — server-level settings, logging, database config + flush logs
- *   Map          — map color threshold configuration
+ *   Server       — server-level settings, logging, database config, map thresholds + flush logs
  *   Regex Tester — live pattern tester
  *   Export       — raw file editors for jail, filter, and action files
  */
@@ -21,7 +20,6 @@ import {
   FiltersTab,
   JailsTab,
   LogTab,
-  MapTab,
   RegexTesterTab,
   ServerTab,
 } from "../components/config";
@@ -57,7 +55,6 @@ type TabValue =
   | "filters"
   | "actions"
   | "server"
-  | "map"
   | "regex"
   | "log";
 
@@ -87,7 +84,6 @@ export function ConfigPage(): React.JSX.Element {
         <Tab value="filters">Filters</Tab>
         <Tab value="actions">Actions</Tab>
         <Tab value="server">Server</Tab>
-        <Tab value="map">Map</Tab>
         <Tab value="regex">Regex Tester</Tab>
         <Tab value="log">Log</Tab>
       </TabList>
@@ -97,7 +93,6 @@ export function ConfigPage(): React.JSX.Element {
         {tab === "filters" && <FiltersTab />}
         {tab === "actions" && <ActionsTab />}
         {tab === "server" && <ServerTab />}
-        {tab === "map" && <MapTab />}
         {tab === "regex" && <RegexTesterTab />}
         {tab === "log" && <LogTab />}
       </div>

frontend/src/pages/__tests__/ConfigPage.test.tsx

@@ -10,7 +10,6 @@ vi.mock("../../components/config", () => ({
   FiltersTab: () => <div data-testid="filters-tab">FiltersTab</div>,
   ActionsTab: () => <div data-testid="actions-tab">ActionsTab</div>,
   ServerTab: () => <div data-testid="server-tab">ServerTab</div>,
-  MapTab: () => <div data-testid="map-tab">MapTab</div>,
   RegexTesterTab: () => <div data-testid="regex-tab">RegexTesterTab</div>,
   ExportTab: () => <div data-testid="export-tab">ExportTab</div>,
 }));