Revert "Mail list: show who wrote, not everyone involved"

This reverts commit 550b8cf503.

backend/app/api/schemas.py

@@ -17,7 +17,6 @@ class ThreadSummary(BaseModel):
     id: uuid.UUID
     subject: str
     snippet: str
-    senders: list[Address]
     participants: list[Address]
     account_ids: list[uuid.UUID]
     message_count: int

backend/app/api/threads.py

@@ -38,7 +38,6 @@ def _summary(thread: Thread, message_count: int | None = None) -> ThreadSummary:
         id=thread.id,
         subject=thread.subject_norm or "(no subject)",
         snippet=thread.snippet,
-        senders=_addresses(thread.senders),
         participants=_addresses(thread.participants),
         account_ids=list(thread.account_ids),
         # Count only the messages this view actually shows (deleted/spam excluded

backend/app/models.py

@@ -152,13 +152,6 @@ class Thread(Base):
     )
     subject_norm: Mapped[str] = mapped_column(Text, nullable=False)
     snippet: Mapped[str] = mapped_column(Text, nullable=False, server_default=text("''"))
-    # Who WROTE in this thread, newest first. Distinct from `participants`, which
-    # also holds recipients because the subject-fallback threading matches on them
-    # (threader._by_subject). The message list shows senders; conflating the two
-    # put "you" next to every sender in the list.
-    senders: Mapped[list[dict[str, str]]] = mapped_column(
-        JSONB, nullable=False, server_default=text("'[]'")
-    )
     participants: Mapped[list[dict[str, str]]] = mapped_column(
         JSONB, nullable=False, server_default=text("'[]'")
     )

backend/app/threading_/threader.py

@@ -197,16 +197,6 @@ async def denormalize_thread(session: AsyncSession, thread_id: uuid.UUID) -> Non
                 seen_emails.add(email)
                 participants.append({"name": addr.get("name", ""), "email": addr.get("email", "")})
 
-    senders: list[dict[str, str]] = []
-    seen_senders: set[str] = set()
-    for msg in messages:  # newest first => most recent writer leads
-        for addr in msg.from_addr:
-            email = (addr.get("email") or "").lower()
-            if email and email not in seen_senders:
-                seen_senders.add(email)
-                senders.append({"name": addr.get("name", ""), "email": addr.get("email", "")})
-
-    thread.senders = senders
     thread.message_count = len(messages)
     thread.unread_count = sum(1 for m in messages if "\\Seen" not in m.flags)
     thread.has_attachments = any(m.has_attachments for m in messages)