fix(core): font zip cache, monotonic timers, resolver back-off, and other core/common fixes (#654)

* fix(core): font zip cache, monotonic timers, resolver back-off, and other core/common fixes

- font_manager: a .zip font URL is served as its extracted font after a
  restart (the cached-file check returned the archive first); downloads
  use requests with a 30s timeout into a temp file + os.replace.
- api_helper / sync_manager: rate-limit and heartbeat/leader timeouts use
  time.monotonic(); last_request_time and the status file's ts stay
  wall-clock. set_on_new_cycle docstring no longer claims core uses it.
- logo_helper: the placeholder uses the same scaled box as a real logo.
- permission_utils: one _sudo_bash_candidates() helper (with the sudoers
  exact-argv rationale) shared by sudo_remove_directory, which now retries
  the next bash path on a sudo refusal, and install_requirements_file.
- dynamic_team_resolver: failed/empty fetch backs off 5 min; duplicate
  INFO log and contradictory docstring example fixed.
- element_style: scale default looked up through element aliases.
- background_data_service: cache-hit callback runs outside the lock.
- config_arrays: union-aware type check (["array","null"]); stale
  dotToNested() reference removed.
- auto_update_setup: non-dict auto_update reads as off; temp result file
  unlinked when the write fails.
- exceptions: constructors copy the caller's context dict.
- logging_config: StructuredFormatter json.dumps(default=str).
- error_aggregator: removed unused export_path/export_to_file/_auto_export.
- Docstrings: validate_file_upload max_size_mb, raise_on_errors.

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

* fix(sync): retry the status-file rename like the other atomic writers

On Windows os.replace can fail with "Access is denied" while a scanner
briefly holds the target open; config_manager_atomic._replace already
retries that (and re-raises at once on other platforms). The sync status
writer called os.replace directly, which made
test_concurrent_writers_each_use_their_own_temp_file flaky on Windows.

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

---------

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

src/web_interface/config_arrays.py

@@ -2,13 +2,29 @@
 
 A list reaches a plugin-config save keyed by position more often than as a
 list. The settings form posts one field per element (``feeds.custom_feeds.0.name``),
-which ``_set_nested_value`` stores as ``{"0": {"name": ...}}``, and the JSON
-path's dotToNested() in the browser builds the same dict. Validation expects
-an array there, so the save converts them first.
+which ``_set_nested_value`` stores as ``{"0": {"name": ...}}``, and a JSON
+save built by flattening then re-nesting dotted keys carries the same dict.
+Validation expects an array there, so the save converts them first.
 """
 from typing import Any, Dict
 
 
+def _schema_type_is(prop: Any, wanted: str) -> bool:
+    """Whether a schema property is of ``wanted`` type, unions included.
+
+    Mirrors ``_schema_type_is`` in ``web_interface/blueprints/api_v3`` (kept
+    here so src/ doesn't import the Flask blueprint). A union such as
+    ``["array", "null"]`` -- the per-element style overrides, where null means
+    "inherit" -- is still an array for recombining position-keyed inputs.
+    """
+    if not isinstance(prop, dict):
+        return False
+    declared = prop.get('type')
+    if isinstance(declared, list):
+        return wanted in declared
+    return declared == wanted
+
+
 def _is_index_dict(value: Any) -> bool:
     """True for a dict keyed only by list positions ("0", "1", ...), or empty."""
     return isinstance(value, dict) and all(str(k).isdigit() for k in value)
@@ -35,10 +51,9 @@ def coerce_array_shapes(config: Dict[str, Any], schema_props: Dict[str, Any],
     for key, prop_schema in schema_props.items():
         if key not in config or not isinstance(prop_schema, dict):
             continue
-        prop_type = prop_schema.get('type')
         value = config[key]
 
-        if prop_type == 'array':
+        if _schema_type_is(prop_schema, 'array'):
             if _is_index_dict(value):
                 value = config[key] = [value[k] for k in sorted(value, key=lambda k: int(str(k)))]
             if not isinstance(value, list):
@@ -50,11 +65,11 @@ def coerce_array_shapes(config: Dict[str, Any], schema_props: Dict[str, Any],
                     and isinstance(default, list) and len(default) >= min_items):
                 value = config[key] = list(default)
             items_schema = prop_schema.get('items')
-            if (isinstance(items_schema, dict) and items_schema.get('type') == 'object'
+            if (_schema_type_is(items_schema, 'object')
                     and 'properties' in items_schema):
                 for element in value:
                     coerce_array_shapes(element, items_schema['properties'],
                                         short_lists_take_default)
 
-        elif prop_type == 'object' and 'properties' in prop_schema:
+        elif _schema_type_is(prop_schema, 'object') and 'properties' in prop_schema:
             coerce_array_shapes(value, prop_schema['properties'], short_lists_take_default)

src/web_interface/validators.py

@@ -8,11 +8,13 @@ from pathlib import Path
 def validate_file_upload(filename: str, max_size_mb: int = 10, 
                         allowed_extensions: Optional[List[str]] = None) -> Tuple[bool, Optional[str]]:
     """
-    Validate file upload parameters.
+    Validate an upload's filename (not its contents or size).
     
     Args:
         filename: Name of the file
-        max_size_mb: Maximum file size in MB
+        max_size_mb: Unused. Kept so existing callers keep working; this
+            function only sees the filename, so callers must enforce the
+            size limit themselves on the uploaded stream.
         allowed_extensions: List of allowed file extensions (e.g., ['.ttf', '.otf'])
     
     Returns: