fix: address PR review findings

Fix (10 of 15 findings):

plugin-repos/march-madness/requirements.txt:
  Add urllib3>=1.26.0 — manager.py directly imports from urllib3; it was
  an undeclared transitive dependency via requests.

scripts/dev/dev_plugin_setup.sh:
  Restore subshell form (cd "$target_dir" && git pull --rebase) || true
  so the shell's working directory is not permanently changed after the
  if-cd block. Previous fix for SC2015 leaked cwd into the remainder of
  the script.

src/base_classes/sports.py:
  Narrow 'except Exception' to 'except RuntimeError as e' and log via
  self.logger.debug — Path.home() raises only RuntimeError for service
  users; other exceptions should not be silently swallowed.

src/config_service.py:
  Fix stale "MD5 checksum" in ConfigVersion.__init__ docstring (line 40);
  the implementation uses SHA-256 since the Codacy fix.

src/wifi_manager.py:
  Log the last-resort AP enable failure with exc_info=True instead of
  silently passing — failure here means the device may be unreachable.

web_interface/blueprints/pages_v3.py:
  Log the outer metadata pre-load exception at debug level instead of
  swallowing it silently; schema still loads fully below.

src/background_data_service.py:
  Remove unused 'timeout' parameter from shutdown() — executor.shutdown()
  does not accept timeout; update __del__ caller accordingly.

src/font_manager.py:
  Validate URL scheme before urlretrieve — reject non-http/https schemes
  (e.g. file://) to prevent reading local files from config-supplied URLs.

src/plugin_system/plugin_executor.py:
  Simplify redundant except tuple: (PluginTimeoutError, PluginError,
  Exception) → Exception, which already covers the others.

test/test_display_controller.py:
  Mark empty test_plugin_discovery_and_loading as @pytest.mark.skip with
  reason. Move duplicate 'from datetime import datetime' to module header
  and remove the stray mid-module copy.

Skip (5 of 15 findings, with reasons):
  - pytest 9.0.3 concerns: full suite already verified (467 pass, 18 pre-existing)
  - Pillow 12.2.0 API concerns: no deprecated APIs in codebase; tests + Pi smoke test pass
  - diagnose_web_ui.sh sudo validation: set -e already ensures fail-fast on any sudo failure
  - app.py request-logging except: must stay silent (recursive logging risk); annotated
  - app.py SSE file-read except: genuinely transient I/O; annotated

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

test/test_display_controller.py

@@ -1,5 +1,7 @@
 import time
+from datetime import datetime
 from unittest.mock import MagicMock, patch
+import pytest
 
 class TestDisplayControllerInitialization:
     """Test DisplayController initialization and setup."""
@@ -13,18 +15,12 @@ class TestDisplayControllerInitialization:
         assert test_display_controller.plugin_manager is not None
         assert test_display_controller.available_modes == []
 
+    @pytest.mark.skip(reason="No assertions; init logic is covered by test_init_success and fixture setup")
     def test_plugin_discovery_and_loading(self, test_display_controller):
         """Test plugin discovery and loading during initialization."""
-        # Mock plugin manager behavior
         pm = test_display_controller.plugin_manager
         pm.discover_plugins.return_value = ["plugin1", "plugin2"]
         pm.get_plugin.return_value = MagicMock()
-        
-        # Manually trigger the plugin loading logic that happens in __init__
-        # Since we're using a fixture that mocks __init__ partially, we need to verify 
-        # the interactions or simulate the loading if we want to test that specific logic
-        # Note: Testing __init__ logic is tricky with the fixture. 
-        # We rely on the fixture to give us a usable controller.
 
 
 class TestDisplayControllerModeRotation:
@@ -248,5 +244,3 @@ class TestDisplayControllerSchedule:
             with patch.object(controller.config_service, 'get_config', return_value=schedule_config):
                 controller._check_schedule()
                 assert controller.is_display_active is False
-            
-from datetime import datetime