refactor: extract Q10 map compositing into a single render result object

Addresses review feedback that `_render_packet` mutated ~8 trait fields
through 3-4 layers of side-effecting methods, making the trait hard to
review and blurring the state-management / pixel-work boundary.

- Add `roborock/map/b01_q10_render.py`: `render_q10_map()` composes a map
  packet + path + overlays + calibration into one `Q10MapRender` result
  (image + MapData + layers), and owns the erase blanking, world->pixel
  overlay placement, path drawing and calibration policy that previously
  lived on the trait. The whole data flow reads top-to-bottom in one
  function instead of nested mutations.
- `MapContentTrait` is now just state management: it accumulates the pushed
  inputs and rebuilds the single `Q10MapRender` wholesale on each change,
  exposing read-only properties. No more per-field clearing. The derived
  rendering scaffolding (erase zones, header calibration) is off the public
  surface; layers/calibration stay (used by the CLI + frontend compositing).
- Move the geometry/pixel tests to tests/map/test_b01_q10_render.py; the
  trait tests now cover state management.
- `UpdatableTrait` explicitly declares the `DpsUpdatable` protocol so the
  heterogeneous fan-out list's shared shape is documented (the map trait
  satisfies it structurally without being a converter-backed read-model).

Author: tubededentifrice

roborock/devices/traits/b01/q10/common.py

@@ -23,16 +23,20 @@
 class DpsUpdatable(Protocol):
     """A trait that updates itself from the Q10 DPS push stream.
 
-    Implemented by :class:`UpdatableTrait` (read-model traits) and by the map
-    trait, which owns the vector-overlay data points. The ``Q10PropertiesApi``
-    subscribe loop fans each push out to every such trait; each picks out the
-    data points it is responsible for and ignores the rest.
+    The ``Q10PropertiesApi`` subscribe loop fans each push out to every trait in
+    its ``_updatable_traits`` list; each picks out the data points it is
+    responsible for and ignores the rest. That list is heterogeneous -- most
+    members are converter-backed :class:`UpdatableTrait` read-models, but the map
+    trait implements ``update_from_dps`` directly to decode the vector overlays it
+    owns without a read-model. This Protocol is the shared shape the loop needs;
+    :class:`UpdatableTrait` declares it explicitly and the map trait satisfies it
+    structurally.
     """
 
     def update_from_dps(self, decoded_dps: dict[B01_Q10_DP, Any]) -> None: ...
 
 
-class UpdatableTrait(TraitUpdateListener):
+class UpdatableTrait(TraitUpdateListener, DpsUpdatable):
     """Base for Q10 traits backed by a read-model updated from the DPS stream.
 
     Concrete traits subclass both their ``RoborockBase`` read-model and this