The foundation for the new settings page. No visible UI change. - app/uilayout.py: screen -> group -> part -> field for every option in config.yaml (67 fields, 11 derived, 0 hidden), with control, unit, display scale, step, entity kind, show conditions, Simple/wizard placement and "applies after a restart". Ranges stay in the schema, words in translations and the new app/ui_text/en.json. - app/uimodel.py: options_to_ui()/ui_to_options() for the derived keys (one inverter vs the list, solar rows, static_profile from simple prices, a year-stamped region preset for the levies figure, and an OPT-11 hook for arbitrage_enabled that changes nothing yet). Unchanged derivations write the stored values back, so the round trip is exact. - validate.py: validate.Note, a warn/info tier. Each logged warning is also a note when a list is passed; config_notes() adds checks that need live data (missing entity, a kW sensor read as W, a limit below this month's peak). /config/validate returns them as "notes". No refusal changed: 261 recorded validator calls, 0 differ (tools/ux13_validator_calls.py). - GET ha/entities: Home Assistant's entity list for the picker, read through hass.states(), cached 30 s, 10 s timeout. When HA is down it answers 200 with the old list marked old, or an empty list that says why. - DECISIONS/UX-13-one-layout-table.md amends UX-02's "no option key in UI code": keys may appear in uilayout.py and uimodel.py only, both tested. - Tests: test_uilayout, test_uimodel (round trip over the recorded calls, the TEST-23 option files and config.yaml defaults), test_haentities, a warning-tier part in test_validate; test_messages scans notes and ui_text; test_pv and test_selfconfig part 7 widened on purpose. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01LyR88rXETvwhTgx6yHE39p