Enhance API and frontend components for character management and map visibility

- Updated API documentation to include `ownedByMe` field in character responses, indicating if a character was last updated by the current user's tokens.
- Modified MapView component to track and display the live status based on user-owned characters.
- Enhanced map data handling to exclude hidden maps for non-admin users and improved character icon representation on the map.
- Refactored character data structures to support new properties and ensure accurate rendering in the frontend.

docs/api.md

@@ -24,9 +24,9 @@ The API is available under the `/map/api/` prefix. Requests requiring authentica
 ## Map data
 
 - **GET /map/api/config** — client configuration (title, auths). Requires a session.
-- **GET /map/api/v1/characters** — list of characters on the map (requires `map` permission; `markers` permission needed to see data).
+- **GET /map/api/v1/characters** — list of characters on the map (requires `map` permission; `markers` permission needed to see data). Each character object includes `ownedByMe` (boolean), which is true when the character was last updated by one of the current user's upload tokens.
 - **GET /map/api/v1/markers** — markers (requires `map` permission; `markers` permission needed to see data).
-- **GET /map/api/maps** — list of maps (filtered by permissions and hidden status).
+- **GET /map/api/maps** — list of maps (filtered by permissions and hidden status). For non-admin users hidden maps are excluded; for admin, the response may include hidden maps (client should hide them in map selector if needed).
 
 ## Admin (all endpoints below require `admin` permission)