- config.py: add temp_warn_c (46°C), temp_crit_c (55°C), bad_block_threshold (0), app_version
- settings_store.py: expose all new fields + system settings (truenas_base_url, api_key, poll_interval, etc.) as editable; save to JSON for persistence; add validation for log_level, poll/stale intervals, temp range
- renderer.py: _temp_class() now reads temp_warn_c/temp_crit_c from settings instead of hardcoded 40/50
- burnin.py: precheck uses settings.temp_crit_c; fix NameError bug (_execute_stages referenced 'profile' that was not in scope)
- routes.py: add GET /api/v1/updates/check (Forgejo releases API); settings_page passes new editable fields; save_settings skips empty truenas_api_key like smtp_password
- settings.html: move system settings from read-only card into editable form; add temp/bad-block fields to Burn-In Behavior; add Check for Updates button; restart-required indicator on save
- history.html: add Completed (finished_at) column next to Started
- app.css: toast container shifts up when drawer is open (body.drawer-open)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>