Data groups: a provider's models read only their own group's data

Every connection is in a data group. Its models are handed, and can find,
only that group's memories, notes, skills, knowledge, reports and
personality -- by search and by id. A chat stays in the group it was
started in: switching its model, the endpoint fallback, the crowd, friends,
bases and the @ menu all stay inside it, and a chat whose model has moved
is refused rather than sent. A group may name its own embedder and image
reviewer. data.manage lets a person make personal groups, remap
connections for themselves and move their own records.

Also: a search no longer mixes two embedders of the same width.

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

src/lembas/db/models/report.py

@@ -6,6 +6,7 @@ from sqlalchemy import Boolean, ForeignKey, String, Text
 from sqlalchemy.orm import Mapped, mapped_column
 
 from lembas.db.base import Base, Timestamps, UUIDPrimaryKey
+from lembas.db.models.data_group import InDataGroup
 
 # Where a report came from. Not a foreign key to anything -- see `source_id`.
 SOURCE_SCHEDULE = "schedule"
@@ -14,7 +15,7 @@ SOURCE_MANUAL = "manual"
 SOURCES = (SOURCE_SCHEDULE, SOURCE_CHAT, SOURCE_MANUAL)
 
 
-class Report(UUIDPrimaryKey, Timestamps, Base):
+class Report(UUIDPrimaryKey, Timestamps, InDataGroup, Base):
     """A finished piece of work, filed.
 
     Deliberately not a `Chat` with one `Message` in it. A report is read top to