make watchlist fully manual; add price + day-change, two-block overview

Per design decision: the watchlist is now purely user-curated (no auto-seeding
of the top-10), so the auto_populate/dismissed machinery is removed and removals
are plain deletes. Each entry is enriched with latest close + day-over-day move.

Overview now shows two clear blocks: Top Setups (what to trade) and My Watchlist
(my names with current price and today's %). Market watchlist table drops the
now-meaningless auto/manual Type column in favour of Price and Day columns.

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

app/schemas/watchlist.py

@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-from datetime import datetime
+from datetime import date, datetime
 from typing import Literal
 
 from pydantic import BaseModel, Field
@@ -33,4 +33,7 @@ class WatchlistEntryResponse(BaseModel):
     rr_ratio: float | None = None
     rr_direction: str | None = None
     sr_levels: list[SRLevelSummary] = []
+    last_close: float | None = None
+    change_pct: float | None = None
+    price_date: date | None = None
     added_at: datetime