fix(stockbit): bid/offer while trading; drop stale foreign flow

Observed in session on 2026-11-03:

- The regular board trades as STATE_NAME_SESSION_2, not the assumed
  STATE_NAME_MARKET_OPEN, so session quotes hid bid/offer all day. Any
  numbered STATE_NAME_SESSION_<n> now counts as trading; the lunch break
  is STATE_NAME_BREAK.
- In session the order book's fbuy/fsell/fnet were the previous session's
  (equal to IPOT's 2026-11-02 net for BBCA, BBRI and TLKM) and
  has_foreign_bs was false. Foreign figures are kept only when that flag
  is true.

Fixtures for the break, the trading state and an in-session book; the
table names the session ("market open (session 2)").

Claude-Session: https://claude.ai/code/session_01RqPPVeVDrnLoP7NUZmLRxY

ROADMAP.md

@@ -15,8 +15,9 @@ history lives in git.
 - Order book depth without a login: no free source exists (IDX sells delayed
   depth to vendors); `stocks orderbook` needs the user's Stockbit login.
 - Stockbit login follow-ups: intraday OHLCV from the session's `1d` chart;
-  observing the session API's open-market state name (assumed
-  `STATE_NAME_MARKET_OPEN`; `STATE_NAME_MARKET_CLOSED` seen 2026-10-29); an
+  confirming session 1 is `STATE_NAME_SESSION_1` (session 2, `BREAK` and
+  `MARKET_CLOSED` were recorded on 2026-11-03), and when `has_foreign_bs`
+  turns on with the day's foreign figures; an
   opt-in daily refresh so a session outlives the refresh token's week, once
   it is known whether Stockbit caps a session's total life; and the sign-in
   response (`/login/v6/*`, read over DevTools' `Fetch`) as a second signal