Release 0.4.0

Zones, electrical heat sources, windows with ventilation, wind exposure
and recovery, and exchange between adjacent zones, all observational.
docs/MODEL.md documents the equations, units, coefficient meanings,
priors and bounds, learning conditions, forecast assumptions, validation
method and results, and limitations. README gains a configuration guide
for zones, heat sources and windows, the new diagnostics and the
accuracy comparison against the base model. CHANGELOG has upgrade notes
(config entry version 3, rollback needs the backup, renamed Status
attributes). ROADMAP marks the Milestone 2 items now covered; AUDIT
records the design decisions and evidence. AGENTS.md lists the new
modules and the convention that new model terms start at zero and must
beat the base model out of sample before being relied on.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

custom_components/heating_mpc/manifest.json

@@ -9,5 +9,5 @@
   "iot_class": "local_polling",
   "requirements": [],
   "single_config_entry": true,
-  "version": "0.3.0"
+  "version": "0.4.0"
 }