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)

backend/migrations/versions/0019_thread_senders.py

@@ -1,58 +0,0 @@
-"""threads.senders — who wrote, as distinct from who was involved
-
-The message list showed a thread's `participants`, which the threader builds from
-from + to + cc because the subject-fallback join matches on recipients. In a list
-that meant every ordinary email read "Sender, You" — and the "+N" badge counted
-the user themselves.
-
-`senders` holds only the from addresses, newest writer first. Backfilled here so
-existing threads do not have to wait to be touched again.
-
-Revision ID: 0019
-Revises: 0018
-Create Date: 2026-09-18
-"""
-
-from __future__ import annotations
-
-from collections.abc import Sequence
-
-from alembic import op
-
-revision: str = "0019"
-down_revision: str | None = "0018"
-branch_labels: str | Sequence[str] | None = None
-depends_on: str | Sequence[str] | None = None
-
-
-def upgrade() -> None:
-    op.execute("ALTER TABLE threads ADD COLUMN senders jsonb NOT NULL DEFAULT '[]'")
-    # Newest writer first, de-duplicated by lower-cased address, matching what
-    # denormalize_thread computes from now on.
-    op.execute(
-        """
-        WITH ranked AS (
-            SELECT m.thread_id,
-                   lower(a->>'email')                        AS email_key,
-                   jsonb_build_object('name', coalesce(a->>'name', ''),
-                                      'email', coalesce(a->>'email', '')) AS addr,
-                   row_number() OVER (PARTITION BY m.thread_id, lower(a->>'email')
-                                      ORDER BY m.internal_date DESC)       AS dup_rank,
-                   max(m.internal_date) OVER (PARTITION BY m.thread_id, lower(a->>'email'))
-                                                                           AS recency
-            FROM messages m
-            CROSS JOIN LATERAL jsonb_array_elements(m.from_addr) AS a
-            WHERE m.thread_id IS NOT NULL AND coalesce(a->>'email', '') <> ''
-        ),
-        collected AS (
-            SELECT thread_id, jsonb_agg(addr ORDER BY recency DESC) AS senders
-            FROM ranked WHERE dup_rank = 1 GROUP BY thread_id
-        )
-        UPDATE threads t SET senders = c.senders
-        FROM collected c WHERE c.thread_id = t.id
-        """
-    )
-
-
-def downgrade() -> None:
-    op.execute("ALTER TABLE threads DROP COLUMN IF EXISTS senders")