` element outside the SVG, driven by Recharts event handlers that receive the raw data regardless of visual rendering.
+Public API and method signatures are unchanged. All existing tests in `logo_handler_test.go` remain valid with zero changes to the test file.
-### 2.4 Confirmation via Comparison
+**File:** `backend/internal/api/handlers/banner_handler.go` (New)
-All other working charts in the codebase use **literal hex color values** for SVG attributes:
+```
+// BannerHandler wraps ImageUploadHandler for the banner asset.
+type BannerHandler struct {
+ inner *ImageUploadHandler
+}
-| Component | Color Approach | Works |
-|---|---|---|
-| `TopHostsChart` | `HOST_COLORS = ['#6366f1', ...]` literal hex in `` | Yes |
-| `TopAttackingIPsChart` | `const BAR_COLOR = '#6366f1'` literal hex in `` | Yes |
-| `BanTimelineChart` | `const BAN_COLOR = '#3b82f6'` literal hex in `` | Yes |
-| `StatusDistributionChart` | `STATUS_COLORS` map with literal hex in `` | Yes |
-| `TrafficVolumeChart` | `var(--color-brand-500, #6366f1)` CSS variable in `` | **Broken** |
+func NewBannerHandler(db *gorm.DB, dataDir string) *BannerHandler
-Note: `BanTimelineChart` uses `'#3b82f6'` which is exactly the hex equivalent of `--color-brand-500: 59 130 246`.
+func (h *BannerHandler) UploadBanner(c *gin.Context) // delegates to h.inner.UploadAsset
+func (h *BannerHandler) DeleteBanner(c *gin.Context) // delegates to h.inner.DeleteAsset
+```
-### 2.5 Secondary Finding: activeDot Inherits Broken Stroke
+The `AssetConfig` for `BannerHandler`:
+- `FormField: "banner"`
+- `URLSettingKey: "ui.banner_url"`
+- `TypeSettingKey: "ui.banner_type"`
+- `FileBaseName: "banner"`
-The `` also defines `activeDot={{ r: 4 }}` without an explicit `fill`. Recharts derives the active dot fill from the Line's `stroke`. Because the stroke is invalid, the active dot's fill is also unset, making the hover indicator invisible as well (though the tooltip div itself still appears).
+#### 3.1.2 Backend — Route Registration
-### 2.6 Existing Test Coverage Gap
+**File:** `backend/internal/api/routes/routes.go`
-The existing test file at `frontend/src/components/stats/__tests__/TrafficVolumeChart.test.tsx` mocks `ResponsiveContainer`, `YAxis`, and `Tooltip` but does **not** mock the `Line` component. This means no test currently asserts the `stroke` prop value on ``, and the bug could not be caught by the test suite.
+Add after the existing logo route wiring (after line 349):
-### 2.7 Existing E2E Test Coverage Gap
+```go
+// Banner upload/delete — admin only (enforced inside ImageUploadHandler.UploadAsset / DeleteAsset)
+bannerHandler := handlers.NewBannerHandler(db, dataRoot)
+management.POST("/settings/banner", bannerHandler.UploadBanner)
+management.DELETE("/settings/banner", bannerHandler.DeleteBanner)
+```
-`tests/stats.spec.ts` includes a "Traffic Volume chart container" test (line 194) that only checks for the card heading and presence of ` | |