Complete tasks 1-5: UI cleanup, pie chart fix, log path allowlist, activation hardening

Task 1: Remove ActiveBansSection from JailsPage
- Delete buildBanColumns, fmtTimestamp, ActiveBansSection
- Remove Dialog/Delete/Dismiss imports, ActiveBan type
- Update JSDoc to reflect three sections

Task 2: Remove JailDistributionChart from Dashboard
- Delete import and JSX block from DashboardPage.tsx

Task 3: Fix transparent pie chart (TopCountriesPieChart)
- Add Cell import and per-slice <Cell fill={slice.fill}> children inside <Pie>
- Suppress @typescript-eslint/no-deprecated (recharts v3 types)

Task 4: Allow /config/log as safe log prefix
- Add '/config/log' to _SAFE_LOG_PREFIXES in config_service.py
- Update error message to list both allowed directories

Task 5: Block jail activation on missing filter/logpath
- activate_jail refuses to proceed when filter/logpath issues found
- ActivateJailDialog treats all validation issues as blocking
- Trigger immediate _run_probe after activation in config router
- /api/health now reports fail2ban online/offline from cached probe
- Add TestActivateJailBlocking tests; fix existing tests to mock validation

frontend/src/pages/DashboardPage.tsx

@@ -12,7 +12,6 @@ import { BanTable } from "../components/BanTable";
 import { BanTrendChart } from "../components/BanTrendChart";
 import { ChartStateWrapper } from "../components/ChartStateWrapper";
 import { DashboardFilterBar } from "../components/DashboardFilterBar";
-import { JailDistributionChart } from "../components/JailDistributionChart";
 import { ServerStatusBar } from "../components/ServerStatusBar";
 import { TopCountriesBarChart } from "../components/TopCountriesBarChart";
 import { TopCountriesPieChart } from "../components/TopCountriesPieChart";
@@ -160,20 +159,6 @@ export function DashboardPage(): React.JSX.Element {
         </div>
       </div>
 
-      {/* ------------------------------------------------------------------ */}
-      {/* Jail Distribution section                                           */}
-      {/* ------------------------------------------------------------------ */}
-      <div className={styles.section}>
-        <div className={styles.sectionHeader}>
-          <Text as="h2" size={500} weight="semibold">
-            Jail Distribution
-          </Text>
-        </div>
-        <div className={styles.tabContent}>
-          <JailDistributionChart timeRange={timeRange} origin={originFilter} />
-        </div>
-      </div>
-
       {/* ------------------------------------------------------------------ */}
       {/* Ban list section                                                    */}
       {/* ------------------------------------------------------------------ */}