UX-13 P5: Dutch text, STYLE check, DOCS screenshots, period editor

- app/ui_text/nl.json and app/uitext.py: every page word in Dutch, English
  fallback per key; the page picks by browser language. Home's sentences
  move into ui_text `home_words`, so /status?lang=nl builds them in Dutch.
- test_ui_text.py: EN/NL key and placeholder parity, STYLE limits, jargon
  lists for both languages, no inline details, untranslated Dutch caught.
  Shared rules moved unchanged to tools/style_rules.py.
- tools/ux13_screenshots.sh/.py: DOCS screenshots from the demo fixtures in
  headless Chromium; docs/img/ux13/. Battery modes (P3): no screenshot.
- "Other time windows": a list editor (ui.periods) that builds
  static_profile and names bad times, empty prices, overlaps and gaps.

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

STYLE.md

@@ -7,7 +7,7 @@ This applies to everything a home owner or installer reads: notifications, phone
 - **Body**: **one sentence** of at most 25 words, saying what happened and what to do. A **red alarm** may use up to **3 sentences** (70 words, each sentence at most 30 words), so that no action a person must take is lost.
 - **Details**: the last line links to the add-on documentation and names the section with the rest: `Details: add-on documentation, section "<title>" under Notifications.` Background, figures, reason codes and history go there or into the log, never into the body.
 - **Status row**: one sentence of at most 15 words. A **red** row may use up to 3 sentences (30 words), like a red alarm. It shows the live numbers the reader acts on and never an HA entity id. **Banner**: at most 12 words. **Refusal**: at most 30 words, naming the setting by its label and then its key, as `messages.setting()` writes it: “Inverter rating” (max_w), or “Inverter rating” for inverter-b (inverters.max_w) for one inverter in the list. **Option name**: at most 6 words, not counting the group prefix. **Option description**: at most 30 words. Where a value comes from belongs in DOCS.md.
-- **Plan line** (UX-13 Home screen: the plan, tooltips, a battery's "now" line): at most 2 sentences, each at most 12 words. Words from `app/homeview.py`, checked by `test_messages.py` part 8.
+- **Plan line** (UX-13 Home screen: the plan, tooltips, a battery's "now" line): at most 2 sentences, each at most 12 words. Words in `app/ui_text/<lang>.json` under `home_words`, built by `app/homeview.py`, checked by `test_messages.py` part 8. The page's own words, English and Dutch, are checked by `test_ui_text.py`.
 - **Log line** (WARNING/ERROR): one line of at most 25 words **as logged**, with any built text filled in. Log lines stay in English and are not translated. A line that reports a safety reason gives one plain sentence and the reason's code (`STALE_READING`, `OUTPUT_CLAMP`), the evidence an installer searches for. The reason itself, with its figures and limits, goes on a DEBUG line right after it and into the action log, never onto the WARNING/ERROR line. It keeps the shape of a red alarm: at most 3 sentences of at most 30 words. The line as logged has no semicolon, banned word, capitals, "1 times" or "(s)". `test_messages.py` part 6 builds every such text with the real code and checks it, and lists the few non-safety families still over 25 words. A line that repeats every cycle is DEBUG. INFO lines carry no section numbers, ISO timestamps or capitals.
 - **Refusal length is counted as shown**: a setting placeholder counts as its label and key, and the long cases are driven through the validator (`test_messages.py` part 3).
 - **Event line** under the buttons: the plain words of `messages.hint()`, like a green row. The add-on's own action log stays technical and is not shown on the page. Installers read it as `events` in the `status` JSON.