feat: company names for tickers (Alpaca backfill + subtle display)

Store an optional company name on Ticker (migration 014) and backfill it from
Alpaca's asset list in a single Trading-API call for the whole universe — no
per-ticker fetch. Runs automatically at the end of universe bootstrap and via a
manual "Backfill Names" button (admin) / POST /admin/tickers/backfill-names.

The name ships on /tickers; a shared symbol→name map (useTickerNames) lets any view
show it without its own request. Displayed subtly next to the symbol — in the global
search, the ticker header, and as a small muted line under the symbol in Top Setups
and Open Trades (no extra column, truncated so it never widens the table).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

alembic/versions/014_add_ticker_name.py

@@ -0,0 +1,29 @@
+"""add name to tickers
+
+Company name (e.g. "Biogen Inc."), backfilled from Alpaca so the UI can show which
+company is behind a symbol. Nullable — symbols Alpaca doesn't cover stay name-less.
+
+Revision ID: 014
+Revises: 013
+Create Date: 2026-07-01 00:00:00.000000
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = "014"
+down_revision: Union[str, None] = "013"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.add_column("tickers", sa.Column("name", sa.String(length=120), nullable=True))
+
+
+def downgrade() -> None:
+    op.drop_column("tickers", "name")