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/main.py

@@ -58,9 +58,13 @@ async def check_resolutions(
         checked += 1
         if res is None or not res.resolved or res.resolution is None:
             continue
-        pnl = await executor.close_position(
-            market_id, res.resolution, question=pos.get("question") or "",
-        )
+        try:
+            pnl = await executor.close_position(
+                market_id, res.resolution, question=pos.get("question") or "",
+            )
+        except Exception as exc:
+            log.error("Failed to close resolved market %s: %s", market_id, exc)
+            continue
         resolved += 1
         log.info(
             "MARKET_RESOLVED market_id=%s resolution=%.1f pnl=%s | %s",