v0.5.1-rc1 — per-lamp colour temperature (validation build)

Pre-release for hardware validation. Not for general use.

Everything in the released v0.5.0, plus the per-lamp colour-temperature
inversion (#15).

What to check

Before touching anything, confirm nothing changed on upgrade: set the lamp to
2700 K (should look warm/orange) and 6500 K (should look cold/blue). The
extremes are far easier to judge by eye than a mid value.

1. Settings → Devices & Services → Bluetooth Mesh → Configure — the lamp is
   already ticked under Lamps with inverted colour temperature.
2. Download diagnostics — state.inverted_ctl names its address.
3. Untick it, save, and retry 2700 / 6500 K. On a lamp that was already
   correct they should now be swapped: that is the option proving it reaches the
   wire, and therefore that ticking it will fix the lamp in #7.
4. Restart Home Assistant and reopen Configure — it must still be unticked.
5. Re-tick to return to a correct state, and confirm 2700 / 6500 K read right
   again.

Step 4 is the one worth doing carefully. It is the only failure in this batch
that would be silent: if the one-time seed re-ran against an emptied list, the
box would re-tick itself on every restart with nothing in any log to say so.