DisplayIdle::tick() runs every 50ms. After startMcpScreensaver()
sets displayDimmed=true, the next tick saw inactive_ms < 100ms
(user navigated Settings) and called stopScreensaver() ->
overlay deleted in <1s, text tool flash-then-back.
Root cause: idle wake logic (inactive<100ms) + charging guard +
duty-restore all operated on any overlay including MCP override.
Fix: detect MCP active via (drawArea != nullptr || overrideActive)
under state.mutex, guard all auto-stop paths with !isMcpActive.
MCP still closable via click handler on overlay (CLICKABLE flag).
Test: flash es3c28p 2be0c0 31% free to /dev/cu.usbmodem101
192.168.68.113 dashboard 200, dev 6666 ok, /api/mcp 25 tools.
Requires PYTHONPATH cleaned for idf.py build (Hermes venv hijacks
pydantic_core).
Adolfo Reyna
6235fa0541