feat v1.12.0: Quality Scale conformance (phases 7-8)

- entry.runtime_data (HouseplanData in store.py) instead of hass.data; WS answers
  not_ready without a loaded entry
- test-before-setup (ConfigEntryNotReady), async_unload_entry, async_remove_entry
  (Lovelace resource cleanup), single_config_entry in manifest
- Store minor_version + migration hook; diagnostics.py (redacted); repairs
  (broken_plan issues, en/ru); system_health.py; strings.json
- quality_scale.yaml self-assessment; HA-harness tests (config flow, WS, upload)
  in CI on py3.13; CI backend job updated

custom_components/houseplan/diagnostics.py

@@ -0,0 +1,41 @@
+"""Diagnostics for House Plan (Settings → ... → Download diagnostics)."""
+from __future__ import annotations
+
+from typing import Any
+
+from homeassistant.components.diagnostics import async_redact_data
+from homeassistant.core import HomeAssistant
+
+from .store import HouseplanConfigEntry
+
+# Marker metadata may contain personal notes, external links and manual filenames.
+TO_REDACT = {"link", "description", "pdfs", "name"}
+
+
+async def async_get_config_entry_diagnostics(
+    hass: HomeAssistant, entry: HouseplanConfigEntry
+) -> dict[str, Any]:
+    """Return a redacted dump of the stores."""
+    data = entry.runtime_data
+    cfg_raw = await data.config_store.async_load() or {}
+    layout_raw = await data.store.async_load() or {}
+    config = cfg_raw.get("config", {})
+    layout = layout_raw.get("layout", {})
+    return {
+        "options": dict(entry.options),
+        "rev": cfg_raw.get("rev", 0),
+        "spaces": [
+            {
+                "id": s.get("id"),
+                "aspect": s.get("aspect"),
+                "has_plan": bool(s.get("plan_url")),
+                "rooms": len(s.get("rooms", [])),
+                "rooms_with_area": sum(1 for r in s.get("rooms", []) if r.get("area")),
+                "segments": len(s.get("segments", [])),
+            }
+            for s in config.get("spaces", [])
+        ],
+        "markers": async_redact_data(config.get("markers", []), TO_REDACT),
+        "settings": config.get("settings", {}),
+        "layout_entries": len(layout),
+    }