v0.2.0 — Heatmap thermal overlay

What's new

Thermal heatmap overlay

A small thermometer icon in the card header cycles through four modes:

Mode	Icon	What it shows
Off	grey thermometer	Normal behaviour — no overlay
Temperature	orange thermometer	Blurred colour-by-temperature across a blue→red ramp
Humidity	blue water-percent	Scattered droplets, density proportional to humidity
Combined	purple blur	Both layers together

The overlay is session-only — clicking the toggle never touches your dashboard YAML.

How the thermal layer works

• One blurred SVG <rect> per room, filled with a colour interpolated across five stops (blue → teal → yellow → orange → red)
• feGaussianBlur at stdDeviation 42 softly blends adjacent room colours at boundaries — drone-thermal aesthetic
• Rooms without a temperature sensor show as neutral grey

How the humidity layer works

• Droplets are placed using a seeded PRNG (mulberry32) keyed to the room ID, so positions are stable across every re-render
• Density scales with humidity above the configurable floor value
• No droplets shown below humidity_floor % (default: 50)

New config schema

heatmap_mode: off          # or: temperature | humidity | combined
humidity_floor: 50         # hide droplets below this humidity %
temperature_range: [16, 26] # card-level default range

floors:
  - temperature_range: [14, 28]  # per-floor override
    rooms:
      - id: garden
        heatmap: false           # opt-out outdoor/sensorless rooms

Existing behaviour preserved

• Light spill glow (box-shadow) is unaffected — shadows render outside the box regardless of background
• Room tap and long-press handlers still fire (SVG has pointer-events: none)
• Info cards, temperature/humidity readouts, occupancy dots and MDI icons remain visible