Add `is_expired()` and harden `.ib.venues` helpers

Add an expiry-date predicate and guard venue session
lookups against expired contracts and empty session
lists in `.ib.venues`; use in `api.py` to skip gap
detection for expired tracts.

Deats,
- add `is_expired()` predicate using
  `pendulum.parse()` on `realExpirationDate`.
- `sesh_times()`: raise `ValueError` if contract is
  expired or has no session intervals (instead of
  `StopIteration` from `next(iter(...))`).
- `is_venue_closure()`: handle `None` return from
  `sesh_times()` with guard + `breakpoint()`.

Also in `api.py`,
- import and call `is_expired()` from `.venues`.
- gate gap-detection on `not _is_expired`.
- default `timeZoneId` to `'EST'` when IB returns
  empty/`None`.

(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code

piker/brokers/ib/api.py

@@ -95,6 +95,7 @@ from .symbols import (
 )
 from ...log import get_logger
 from .venues import (
+    is_expired,
     is_venue_open,
     sesh_times,
     is_venue_closure,
@@ -496,7 +497,7 @@ class Client:
                 await self.ib.reqContractDetailsAsync(contract)
             )[0]
             # convert to makt-native tz
-            tz: str = details.timeZoneId
+            tz: str = details.timeZoneId or 'EST'
             end_dt = end_dt.in_tz(tz)
             first_dt: DateTime = from_timestamp(first).in_tz(tz)
             last_dt: DateTime = from_timestamp(last).in_tz(tz)
@@ -508,10 +509,18 @@ class Client:
             _open_now: bool = is_venue_open(
                 con_deats=details,
             )
+            _is_expired: bool = is_expired(
+                con_deats=details,
+            )
 
             # XXX, do gap detections.
             has_closure_gap: bool = False
             if (
+                # XXX, expired tracts can't be introspected
+                # for open/closure intervals due to ib's chitty
+                # details seemingly..
+                not _is_expired
+                and
                 last_dt.add(seconds=sample_period_s)
                 <
                 end_dt

piker/brokers/ib/venues.py

@@ -34,6 +34,7 @@ from typing import (
 
 import exchange_calendars as xcals
 from pendulum import (
+    parse,
     now,
     Duration,
     Interval,
@@ -56,6 +57,17 @@ if TYPE_CHECKING:
     )
 
 
+def is_expired(
+    con_deats: ContractDetails,
+) -> bool:
+    '''
+    Predicate 
+
+    '''
+    expiry_dt: datetime = parse(con_deats.realExpirationDate)
+    return expiry_dt.date() >= now().date()
+
+
 def has_weekend(
     period: Interval,
 ) -> bool:
@@ -170,7 +182,22 @@ def sesh_times(
     get the (day-agnostic) times for the start/end.
 
     '''
-    earliest_sesh: Interval = next(iter_sessions(con_deats))
+    # ?TODO, lookup the next front contract instead?
+    if is_expired(con_deats):
+        raise ValueError(
+            f'Contract is already expired!\n'
+            f'Choose an active alt contract instead.\n'
+            f'con_deats: {con_deats!r}\n'
+        )
+
+    maybe_sessions: list[Interval] = list(iter_sessions(con_deats))
+    if not maybe_sessions:
+        raise ValueError(
+            f'Contract has no trading-session info?\n'
+            f'con_deats: {con_deats!r}\n'
+        )
+
+    earliest_sesh: Interval = maybe_sessions[0]
     return (
         earliest_sesh.start.time(),
         earliest_sesh.end.time(),
@@ -211,7 +238,13 @@ def is_venue_closure(
     '''
     open: Time
     close: Time
-    open, close = sesh_times(con_deats)
+    maybe_oc: tuple|None = sesh_times(con_deats)
+    if maybe_oc is None:
+        # XXX, should never get here.
+        breakpoint()
+        return False
+
+    open, close = maybe_oc
 
     # ensure times are in mkt-native timezone
     tz: str = con_deats.timeZoneId