v0.7.2

Added

• Removing a heater (#18).
  • In HA: deleting a heater's device (device page, ⋮ → Delete) has
    the relay forget it too, then removes its entities and frees its number.
    It's refused while the heater is still reporting, since it would come
    back on its next boot.
  • Relay: DELETE /heaters/<dsn>?confirm=<dsn> deletes the heater's
    directory (key, saved config, queue). For the primary it also deletes the
    PRIMARY marker and the single-heater files kept for downgrades, which
    used to rebuild it. The relay then restarts in-process from what's left
    on disk.
    • 409 (unless force=1) while the heater is reporting or has a LAN
      session, or within ten minutes of a relay restart if it hasn't reported
      yet.
    • 409 if module_ip or device_dsn names the primary.
    • The single-heater files and the marker are deleted only if they're the
      removed heater's own.
    • A stop signal during the restart still stops the relay.
    • The state API answers 503 until the restart finishes.
  • To replace the primary heater and keep its entities, forget it on the
    relay only, without deleting the HA device. The new heater then takes
    over the old one's entities. See docs/MULTI_HEATER.md.

Added

• Multi-heater guide, docs/MULTI_HEATER.md (#18,
  phase 4): adding a heater, telling heaters apart, service targets, the
  primary heater and the relay's per-heater API, and limits.
• docs/dashboard-multi.yaml: a two-heater
  view with a column per heater and shared 24-hour graphs. A test checks it
  against a two-heater install.