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/main.py

@@ -5544,7 +5544,7 @@ class Controller:
                                 _inv_list.index(ent) + 1)})
         return out
 
-    def status_payload(self) -> dict:
+    def status_payload(self, lang: str = "en") -> dict:
         checks = self.checks()
         bad = [c for c in checks if not c["ok"] and not c["warn"]]
         # --- SAFETY-10, AND IT IS FIRST IN THE CASCADE -----------------------
@@ -5730,7 +5730,8 @@ class Controller:
         # never cost the page its rows: a fault here is logged and the old
         # fields are served alone (the page then shows the installer details).
         try:
-            out.update(homeview.build(self, level=level, checks=checks))
+            out.update(homeview.build(self, level=level, checks=checks,
+                                      lang=lang))
         except Exception:                               # noqa: BLE001
             # Once per process at ERROR: the page polls every 3 s.
             if not getattr(self, "_home_failed", False):