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>

goodwe_controller/app/setuponly.py

@@ -52,7 +52,7 @@ class SetupOnly:
         if hint is not None:
             self.hint = f"{datetime.now().astimezone():%H:%M} {hint}"
 
-    def status_payload(self) -> dict:
+    def status_payload(self, lang: str = "en") -> dict:
         return {"setup_only": True, "mode": "setup_only",
                 "banner": messages.banner_setup_only(), "level": "warn",
                 "rows": [["Control", "not started, in setup"]],