Adds a + button to the chat input bar (between handle + message field) that opens a small photo/video menu. Photo picks the native camera-roll/photo picker (api.file), downscales to <=1024px, uploads via the existing painting pipeline (api.upload -> track-media short code), and drops the #code into the input so it renders as the inline preview chat already supports. Drag-drop of an image runs the same path. Video sits as 'soon' (Phase 2: camera-roll video -> !tape, reusing the tape mp4 container). Requested by hvad93 in laer-klokken.