Handle `str`-errors in `.ib.broker` trade events

Add `isinstance()` dispatch for the `'error'` event case in
`deliver_trade_events()` to handle `ib_async` sometimes emitting plain
`str` error items instead of the previously expected `dict`.

Deats,
- add `isinstance(err, dict)` branch for the standard case with
  `error_code`, `reason`, and `reqid` fields.
- add `isinstance(err, str)` branch to parse error strings of the
  form `'[code 104] connection failed'` into `code` and `reason`.
- set `reqid: str = '<unknown>'` for string-form errors since
  there's no request ID available.
- update `err` type annot to `dict|str`.

(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/broker.py

@@ -1291,13 +1291,23 @@ async def deliver_trade_events(
             case 'error':
                 # NOTE: see impl deats in
                 # `Client.inline_errors()::push_err()`
-                err: dict = item
+                err: dict|str = item
 
-                # never relay errors for non-broker related issues
+                # std case, never relay errors for non-order-control
+                # related issues.
                 # https://interactivebrokers.github.io/tws-api/message_codes.html
-                code: int = err['error_code']
-                reason: str = err['reason']
-                reqid: str = str(err['reqid'])
+                if isinstance(err, dict):
+                    code: int = err['error_code']
+                    reason: str = err['reason']
+                    reqid: str = str(err['reqid'])
+
+                # XXX, sometimes you'll get just a `str` of the form,
+                # '[code 104] connection failed' or something..
+                elif isinstance(err, str):
+                    code_part, _, reason = err.rpartition(']')
+                    if code_part:
+                        _, _, code = code_part.partition('[code')
+                    reqid: str = '<unknown>'
 
                 # "Warning:" msg codes,
                 # https://interactivebrokers.github.io/tws-api/message_codes.html#warning_codes

piker/tsp/_history.py

@@ -251,10 +251,20 @@ async def maybe_fill_null_segments(
             end_dt=end_dt,
         )
 
+        if array.size == 0:
+            log.warning(
+                f'Valid gap from backend ??\n'
+                f'{end_dt} -> {start_dt}\n'
+            )
+            # ?TODO? do we want to remove the nulls and push
+            # the close price here for the gap duration?
+            await tractor.pause()
+            break
+
         if (
-            frame_start_dt := (
-                from_timestamp(array['time'][0])
-            ) < backfill_until_dt
+            frame_start_dt := (from_timestamp(array['time'][0]))
+            <
+            backfill_until_dt
         ):
             log.error(
                 f'Invalid frame_start !?\n'
@@ -616,10 +626,17 @@ async def start_backfill(
 
             else:
                 log.warning(
-                    '0 BARS TO PUSH after diff!?\n'
+                    f'0 BARS TO PUSH after diff!?\n'
                     f'{next_start_dt} -> {last_start_dt}'
+                    f'\n'
+                    f'This might mean we rxed a gap frame which starts BEFORE,\n'
+                    f'backfill_until_dt: {backfill_until_dt}\n'
+                    f'end_dt_param: {end_dt_param}\n'
+
                 )
-                await tractor.pause()
+                # XXX, to debug it and be sure.
+                # await tractor.pause()
+                break
 
             # Check if we're about to exceed buffer capacity BEFORE
             # attempting the push