DataSourceConfig refactored to enum: External/Clock/StaticText. Clock
generates formatted time via chrono, static text emits configured string.
ESP32: connection status indicator (green/red dot bottom-right), per-widget
clear before redraw, RenderEvent enum for local + server messages.
Polling uses DataUpdate instead of ScreenUpdate to avoid wiping widget state.
Empty mappings passthrough raw source data for internal sources.
Replace compile-time env!() wifi/server config with NVS-based
runtime provisioning. Boot checks NVS — if no config, starts
AP mode (KFrame-Setup) with DNS responder + HTTP config form.
WiFi failure clears config and reboots into setup mode.
boot logo (procedural hexagon + K), WiFi (WPA auto-detect with retries),
TCP client connects and receives ScreenUpdate/DataUpdate messages,
display renders widget data. Makefile with esp-flash/server/desktop targets.
known issues: boot logo not cleared, text overlaps, occasional reconnect
