fix(web): plugin dir resolver in routes, nmcli AP detection, daemon config reload, upload safety, BDF preview (#655)

* fix(web): plugin dir resolver in routes, nmcli AP detection, daemon config reload, upload safety

- Route plugin lookups (installed list, update, recorded version, config
  form, web UI pages) through the plugin manager's resolver so plugins in
  ledmatrix-<id> directories work.
- Captive-portal detection also sees the nmcli fallback AP (cached).
- WiFi monitor daemon re-reads wifi_config.json when its mtime changes.
- Drop the AP check in disconnect_from_network that could never fire.
- LED status file per WiFiManager; config path falls back to this checkout.
- BDF font preview via src.common.bdf_font.
- Asset uploads validate every file before saving; metadata and calendar
  credentials written atomically; no absolute path in the response;
  asset delete answers 400 for a missing body.
- Coerce string booleans in plugin toggle, on-demand start and AP force.
- SSE broadcaster clears its thread handle before exiting.
- start.py log filter handles every exc_info form.
- Cleanups: unused plugins/fonts partial work, duplicate backup catch-alls,
  raw-config error helper, update-route tidy, redundant imports.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(web): request BDF font previews now that the server renders them

The Fonts tab skipped the preview request for .bdf files because the server
used to refuse them; /fonts/preview now draws BDF with the shared loader.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(web): take the update route's plugin directory from a directory listing

CodeQL flagged the path built from the request's plugin_id (the id was
already validated with safe_path_component, which CodeQL doesn't model; the
same flow on main is alerts 738/739). The directory is now the entry of
plugins_dir matched by name, so nothing built from user input reaches the
filesystem; an id with nothing installed goes to the store manager, which
reports it not found as before.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(web): read the blueprint's plugin_manager defensively in _plugin_directory

_get_plugin_version now goes through _plugin_directory, which read
api_v3.plugin_manager directly; the attribute exists only once the app sets
it, so test_path_traversal_guards::test_a_real_manifest_is_read failed
when run on its own (order-dependent in the full suite).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

web_interface/start.py

@@ -17,6 +17,21 @@ logger = logging.getLogger('web_interface.start')
 _CLIENT_DISCONNECT_ERRNOS = (113, 32, 104)
 
 
+def _exc_info_value(exc_info):
+    """The exception a logging call's ``exc_info`` argument refers to.
+
+    logging accepts a (type, value, traceback) tuple, an exception instance,
+    or True for the exception being handled. The werkzeug filter below used
+    to unpack it as a tuple, so True or an instance raised TypeError from
+    inside the logging call itself.
+    """
+    if isinstance(exc_info, BaseException):
+        return exc_info
+    if isinstance(exc_info, tuple):
+        return exc_info[1] if len(exc_info) > 1 else None
+    return sys.exc_info()[1]
+
+
 def get_local_ips():
     """Get list of local IP addresses the service will be accessible on."""
     ips = []
@@ -94,7 +109,7 @@ def main():
                 return
         # For exceptions, check if it's a socket error
         if 'exc_info' in kwargs and kwargs['exc_info']:
-            exc_type, exc_value, exc_tb = kwargs['exc_info']
+            exc_value = _exc_info_value(kwargs['exc_info'])
             if isinstance(exc_value, OSError):
                 if exc_value.errno in _CLIENT_DISCONNECT_ERRNOS:
                     werkzeug_logger.debug(message, *args, **kwargs)