fix(resolution): cast $3 explicitly in close_paper_position and persist before mutating portfolio

Cycle-10 resolution check found market 562186 resolved (Paxton YES) but the
close failed with asyncpg AmbiguousParameterError: Postgres cannot infer the
type of a bare '$3 IS NOT NULL' in the close_pnl CASE. Reproduced via PREPARE
in the postgres pod; fixed by casting every $3 use to double precision.

The failed DB write also left memory/DB diverged: close_position() popped the
position and credited cash before persisting, so the retry at cycle 20 skipped
the market (pnl=n/a) while the DB row stayed open. Now the DB write happens
first and memory mutates only on success; check_resolutions() also isolates
per-market close failures so one error doesn't abort the cycle.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

bot/data/db.py

@@ -176,15 +176,18 @@ class Database:
         is computed in SQL so it matches the stored entry_price and shares exactly.
         """
         async with self._pool.acquire() as conn:
+            # $3 is cast on every use: Postgres cannot infer the parameter type
+            # from a bare "$3 IS NOT NULL" and fails the prepare with
+            # AmbiguousParameterError otherwise.
             await conn.execute("""
                 UPDATE trades
                 SET closed_at    = NOW(),
                     close_reason = $2,
-                    resolution   = $3,
+                    resolution   = $3::double precision,
                     close_pnl    = CASE
-                        WHEN $3 IS NOT NULL AND direction = 'BUY_YES'
+                        WHEN $3::double precision IS NOT NULL AND direction = 'BUY_YES'
                             THEN ($3::double precision - entry_price) * shares
-                        WHEN $3 IS NOT NULL AND direction = 'BUY_NO'
+                        WHEN $3::double precision IS NOT NULL AND direction = 'BUY_NO'
                             THEN ((1.0 - $3::double precision) - entry_price) * shares
                         ELSE NULL
                     END