Use `tn` for nursery vars in UI modules

Rename `root_n` -> `tn` in `_app.py` and
`ln` -> `tn` in `_display.py` to match the `trio` nursery naming
convention used elsewhere. Drop a couple stray blank lines.

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

piker/config.py

@@ -37,6 +37,7 @@ except ModuleNotFoundError:
 
 
 from tractor._exceptions import reg_err_types
+from tractor.devx.pformat import ppfmt
 from .log import get_logger
 
 log = get_logger('broker-config')
@@ -357,30 +358,56 @@ def write(
 
 
 def load_accounts(
-    providers: list[str] | None = None
-
-) -> bidict[str, str | None]:
+    providers: list[str]|None = None
+) -> bidict[str, str|None]:
 
     conf, path = load(
         conf_name='brokers',
     )
-    accounts = bidict()
-    for provider_name, section in conf.items():
-        accounts_section = section.get('accounts')
+    accounts = bidict({
+        # XXX, default paper-engine entry; this MUST be set.
+        'paper': None,
+    })
+    msg: str = (
+        'Loading account(s) from `brokers.toml`,\n'
+    )
+    for (
+        provider_name,
+        section,
+    ) in conf.items():
+        accounts_section: dict[str, str] = section.get('accounts')
+        if accounts_section is None:
+            msg += f'No accounts declared for {provider_name!r}?\n'
+            continue
+
+        # msg += f'Loaded accounts for {provider_name!r}?\n'
         if (
-            providers is None or
-            providers and provider_name in providers
+            providers is None
+            or (
+                providers
+                and
+                provider_name in providers
+            )
         ):
-            if accounts_section is None:
-                log.warning(f'No accounts named for {provider_name}?')
-                continue
-            else:
-                for label, value in accounts_section.items():
-                    accounts[
-                        f'{provider_name}.{label}'
-                    ] = value
+            for (
+                label,
+                value,
+            ) in accounts_section.items():
+                account_alias: str = f'{provider_name}.{label}'
+                accounts[account_alias] = value
+                msg += f'{account_alias} = {value!r}\n'
 
-    # our default paper engine entry
-    accounts['paper'] = None
+        else:
+            log.debug(
+                f'NOT loading account(s) for entry in `brokers.toml`,\n'
+                f'The account provider was not requested for loading.\n'
+                f'requested-providers: {providers!r}\n'
+                f'this-provider: {provider_name!r}\n'
+                f'\n'
+                f'{ppfmt(accounts_section)}\n'
+            )
+            # ?TODO? mk this bp work?
+            # breakpoint()
 
+    log.info(msg)
     return accounts

piker/service/_daemon.py

@@ -218,11 +218,13 @@ async def maybe_spawn_daemon(
             lock.statistics().owner is current_task()
         ):
             log.exception(
-                f'Releasing stale lock after crash..?'
+                f'Releasing stale lock after crash..?\n'
+                f'\n'
                 f'{err!r}\n'
             )
             lock.release()
-            raise err
+
+        raise
 
 
 async def spawn_emsd(

piker/ui/_app.py

@@ -131,11 +131,11 @@ async def _async_main(
 
     async with (
         tractor.trionics.collapse_eg(),
-        trio.open_nursery() as root_n,
+        trio.open_nursery() as tn,
     ):
         # set root nursery and task stack for spawning other charts/feeds
         # that run cached in the bg
-        godwidget._root_n = root_n
+        godwidget._root_n = tn
 
         # setup search widget and focus main chart view at startup
         # search widget is a singleton alongside the godwidget
@@ -165,7 +165,7 @@ async def _async_main(
             # load other providers into search **after**
             # the chart's select cache
             for brokername, mod in needed_brokermods.items():
-                root_n.start_soon(
+                tn.start_soon(
                     load_provider_search,
                     mod,
                     loglevel,

piker/ui/_display.py

@@ -1346,7 +1346,6 @@ async def display_symbol_data(
             fqmes,
             loglevel=loglevel,
             tick_throttle=cycles_per_feed,
-
         ) as feed,
     ):
 
@@ -1461,7 +1460,7 @@ async def display_symbol_data(
 
         async with (
             tractor.trionics.collapse_eg(),
-            trio.open_nursery() as ln,
+            trio.open_nursery() as tn,
         ):
             # if available load volume related built-in display(s)
             vlm_charts: dict[
@@ -1472,7 +1471,7 @@ async def display_symbol_data(
                 flume.has_vlm()
                 and vlm_chart is None
             ):
-                vlm_chart = vlm_charts[fqme] = await ln.start(
+                vlm_chart = vlm_charts[fqme] = await tn.start(
                     open_vlm_displays,
                     rt_linked,
                     flume,
@@ -1480,7 +1479,7 @@ async def display_symbol_data(
 
             # load (user's) FSP set (otherwise known as "indicators")
             # from an input config.
-            ln.start_soon(
+            tn.start_soon(
                 start_fsp_displays,
                 rt_linked,
                 flume,
@@ -1604,11 +1603,11 @@ async def display_symbol_data(
 
             # start update loop task
             dss: dict[str, DisplayState] = {}
-            ln.start_soon(
+            tn.start_soon(
                 partial(
                     graphics_update_loop,
                     dss=dss,
-                    nurse=ln,
+                    nurse=tn,
                     godwidget=godwidget,
                     feed=feed,
                     # min_istream,
@@ -1623,7 +1622,6 @@ async def display_symbol_data(
             order_ctl_fqme: str = fqmes[0]
             mode: OrderMode
             async with (
-
                 open_order_mode(
                     feed,
                     godwidget,