House panel example and the sensor hub it runs on

[bdbarnett]

This lands the P4 house appliance as lib/examples/house/, together with the sensor hub it depends on, which until now lived only on the unmerged spike/scenarios-batch2 branch. Its README starts with what it does:

• the rooms, their thresholds and alerts on the panel;
• the same rooms live on a phone at http://<board ip>/;
• a SHOW-TV button that casts the panel, with the chime, to a Roku.

Real nodes such as the FunHouse take the first cards.

What's in it:

• Commits 1–8: the sensor hub, fleet page and FunHouse node. These are the Batch 0 and Batch 2 work from spike/scenarios-batch0/-batch2, rebased onto main. The only conflicts were in generated files (packages/examples.json, the PyScript TOML), and they're regenerated in the last commit. The spike branches stay as they were.
• The last commit: the house app, plus one small hub change.
  • house_panel (the display, the alerts, SimHouse) and house_app (panel, dashboard and SHOW-TV on one asyncio loop).
  • house_server, the dashboard alone.
  • dashboard.html, the house page.
  • main.py, to boot into it.
  • Hub(..., page=), so an app can serve its own dashboard. The board used to overwrite the hub's dashboard.html instead.

Depends on #154, the cast example. The house app imports roku_cast/castfast from the example beside it when you press SHOW-TV, and it needs the P4 firmware with castif (PyDevices/micropython-pydevices#27). Merge #154 first.

Evidence, from the spike copy that ran as the P4's boot app on 2026-09-27:

• The panel showed the FunHouse card, and Brad confirmed its numbers agreed with the FunHouse's own screen.
• The dashboard answered at the board's address.
• SHOW-TV cast the panel to the 65". Brad noted the TV redraws about once a second, because the panel only changes that often.

The landed copy differs from that one only in how it's imported. It no longer uses /cast paths, it no longer writes a painter-error log to flash (a flash write stalls a running cast), and it serves the house page through page=. That landed copy hasn't run on the board yet; it gets proven after merge, when the P4 is rebuilt from main.

Marked # gallery: skip: it needs the board.

[bdbarnett]

The landed copy now runs on the board. The P4, on the #27 landing image, boots this branch's house/main.py with cast, house, sensor_hub and roku_remote/roku_engine.py installed to /lib the way mip lays them out. The panel is up. http://<board>/ serves the house page through Hub(page=) (title "PyDevices House"), and /api/readings lists the funhouse node over HTTP beside the four simulated rooms. SHOW-TV hasn't been pressed on this copy yet.