sync: recipients keep their own pin, archive and place on shared notes

A note_user_state row per (note, recipient) holds what used to be the owner's
columns as far as anyone else could tell. The board filters and orders through
the viewer's own state; PATCH and reorder write it for a note shared at any
level; the feed's revision for a shared note is the later of the note's and the
caller's row, so a recipient's pin reaches their devices and no one else's.

Push takes the three with their own `state_at` stamp (protocol 7,
`shared_state`), so pinning a copy whose text is behind never makes that text
win over the owner's edit. A body is only stamped as an edit when it changed.

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

alembic/versions/0036_note_user_state.py

@@ -0,0 +1,55 @@
+"""note_user_state: a recipient's own pin, archive and place for a shared note
+
+Revision ID: 0036
+Revises: 0035
+Create Date: 2026-10-07
+
+Pin, archive and board order are personal organization, and until now they were
+columns on `notes`, so on a shared note they could only ever mean the owner's
+(#5176). This table holds them for everyone else: one row per (note, person it is
+shared with) who has pinned, archived or moved it. The owner keeps the note's own
+columns; a recipient with no row sees the note unpinned, unarchived, in the owner's
+order.
+
+`sync_revision` is stamped by the same `ts_set_sync_revision()` trigger the notes
+and labels use (0015), so a recipient's change reaches their own devices on the one
+cursor they already page by, and never moves the note on anyone else's.
+
+## Downgrade
+
+Drops the table. Recipients lose their own pins and archives; the notes are
+untouched.
+"""
+import sqlalchemy as sa
+from alembic import op
+from sqlalchemy.dialects.postgresql import UUID
+
+revision = "0036"
+down_revision = "0035"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "note_user_state",
+        sa.Column("note_id", UUID(as_uuid=True), sa.ForeignKey("notes.id", ondelete="CASCADE"), nullable=False),
+        sa.Column("user_id", UUID(as_uuid=True), sa.ForeignKey("users.id", ondelete="CASCADE"), nullable=False),
+        sa.Column("pinned", sa.Boolean(), nullable=False, server_default=sa.false()),
+        sa.Column("archived", sa.Boolean(), nullable=False, server_default=sa.false()),
+        sa.Column("position", sa.Integer(), nullable=True),
+        sa.Column("updated_at", sa.DateTime(timezone=True), nullable=False, server_default=sa.func.now()),
+        sa.Column("sync_revision", sa.BigInteger(), nullable=True),
+        sa.PrimaryKeyConstraint("note_id", "user_id"),
+    )
+    op.create_index("ix_note_user_state_user_revision", "note_user_state", ["user_id", "sync_revision"])
+    op.execute(
+        "CREATE TRIGGER trg_note_user_state_sync_revision BEFORE INSERT OR UPDATE ON note_user_state "
+        "FOR EACH ROW EXECUTE PROCEDURE ts_set_sync_revision()"
+    )
+
+
+def downgrade() -> None:
+    op.execute("DROP TRIGGER IF EXISTS trg_note_user_state_sync_revision ON note_user_state")
+    op.drop_index("ix_note_user_state_user_revision", table_name="note_user_state")
+    op.drop_table("note_user_state")