fix(a11y): improve settings dialog UX and label associations

[Orinks]

Summary

This PR started as a settings dialog UX cleanup, then expanded into a full accessibility pass after NVDA exposed label-association problems in the dialog.

What changed:

• reorganizes the settings dialog into clearer task-oriented sections and tab flow
• improves labels, helper copy, summary text, and save-action wording across the dialog
• replaces static-box section patterns that caused wx/NVDA to announce group labels as if they belonged to the first control
• introduces a shared helper that creates the visible label before its control, then converts affected settings rows across tabs to use that pattern
• fixes forecast-range labeling confusion and stabilizes daily/hourly forecast control announcements
• removes remaining problematic section/grouping patterns in provider key areas and event sound configuration
• adds regression coverage around settings-dialog accessibility structure and label/control creation order

Files changed

• src/accessiweather/ui/dialogs/settings_dialog.py
• src/accessiweather/ui/dialogs/settings_tabs/advanced.py
• src/accessiweather/ui/dialogs/settings_tabs/ai.py
• src/accessiweather/ui/dialogs/settings_tabs/audio.py
• src/accessiweather/ui/dialogs/settings_tabs/data_sources.py
• src/accessiweather/ui/dialogs/settings_tabs/display.py
• src/accessiweather/ui/dialogs/settings_tabs/general.py
• src/accessiweather/ui/dialogs/settings_tabs/notifications.py
• src/accessiweather/ui/dialogs/settings_tabs/updates.py
• tests/test_dialog_accessibility.py
• tests/test_settings_dialog_audio_events.py
• tests/test_settings_dialog_ux_metadata.py

Testing

• ruff check src/accessiweather/ui/dialogs/settings_dialog.py src/accessiweather/ui/dialogs/settings_tabs/advanced.py src/accessiweather/ui/dialogs/settings_tabs/ai.py src/accessiweather/ui/dialogs/settings_tabs/audio.py src/accessiweather/ui/dialogs/settings_tabs/data_sources.py src/accessiweather/ui/dialogs/settings_tabs/display.py src/accessiweather/ui/dialogs/settings_tabs/general.py src/accessiweather/ui/dialogs/settings_tabs/notifications.py src/accessiweather/ui/dialogs/settings_tabs/updates.py tests/test_settings_dialog_audio_events.py tests/test_settings_dialog_ux_metadata.py
• pytest -q tests/test_settings_dialog_audio_events.py tests/test_settings_dialog_tray_text.py tests/test_settings_dialog_api_key_guard.py tests/test_settings_dialog_portable_copy.py tests/test_settings_dialog_ux_metadata.py
• pytest -q tests/test_settings_dialog_ux_metadata.py tests/test_dialog_accessibility.py tests/test_settings_dialog_audio_events.py tests/test_settings_dialog_tray_text.py tests/test_settings_dialog_api_key_guard.py tests/test_settings_dialog_portable_copy.py
• PYTHONPATH=src python3 -m pytest -q tests/test_dialog_accessibility.py tests/test_display_tab_unit_labels.py tests/test_settings_dialog_api_key_guard.py tests/test_settings_dialog_audio_events.py tests/test_settings_dialog_portable_copy.py tests/test_settings_dialog_source_priority.py tests/test_settings_dialog_tray_text.py tests/test_settings_dialog_ux_metadata.py

[Orinks]

Accessibility follow-up fixed: section helper descriptions are no longer injected ahead of the first interactive control in each section, so they won't get in the way of the first item's announcement.\n\nVerification:\n- All checks passed!\n- ============================= test session starts ==============================
platform linux -- Python 3.13.5, pytest-8.3.5, pluggy-1.5.0
rootdir: /home/openclaw/projects/AccessiWeather
configfile: pytest.ini
plugins: cov-7.0.0, anyio-4.12.1, timeout-2.4.0, xdist-3.8.0, hypothesis-6.151.9
asyncio: mode=Mode.AUTO, debug=False, asyncio_default_fixture_loop_scope=None, asyncio_default_test_loop_scope=function
created: 2/2 workers
2 workers [41 items]

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============================== 41 passed in 2.11s ==============================