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/test_home.py

@@ -546,12 +546,13 @@ def resolve(path):
     return node
 
 
-check("the page is assembled: no placeholder is left and the words parse",
+_WORDS = json.loads(PAGE.split('id="ui-text">', 1)[1]
+                    .split("</script>", 1)[0].replace("<\\/", "</"))
+check("the page is assembled: no placeholder is left and the words parse, "
+      "English and Dutch (UX-13 P5)",
       "/*APP_CSS*/" not in PAGE and "/*APP_JS*/" not in PAGE
       and "/*UI_TEXT*/" not in PAGE
-      and json.loads(PAGE.split('id="ui-text">', 1)[1]
-                     .split("</script>", 1)[0].replace("<\\/", "</"))["home"]
-      == UI)
+      and _WORDS["en"]["home"] == UI and set(_WORDS) == {"en", "nl"})
 check("four tabs with the four hash routes, in a keyboard tablist",
       re.findall(r'data-hash="(\w+)"', PAGE) == ["home", "batteries",
                                                  "settings", "setup"]
@@ -563,7 +564,7 @@ check(f"no external file and no web font: no URL leaves the add-on "
       and "<link" not in PAGE and "src=" not in PAGE)
 _abs = re.findall(r"""(?:fetch\(|href=)["'](/[^"']*)["']""", PAGE)
 check(f"every fetch and link is relative, for ingress ({_abs})",
-      not _abs and 'fetch("status"' in JS and 'fetch("action"' in JS)
+      not _abs and 'fetch("status?lang=' in JS and 'fetch("action"' in JS)
 _keys = set(re.findall(r'data-t(?:-label)?="([\w.]+)"', PAGE)) | set(
     re.findall(r'''\bt\("([\w.]+)"\)''', JS))
 _missing = sorted(k for k in _keys if not isinstance(resolve(k), str))
@@ -610,6 +611,8 @@ async def _serve():
                 out["page"] = (r.status, r.content_type, await r.text())
             async with s.get(f"http://127.0.0.1:{port}/status") as r:
                 out["status"] = await r.json()
+            async with s.get(f"http://127.0.0.1:{port}/status?lang=nl-BE") as r:
+                out["status_nl"] = await r.json()
             async with s.get(f"http://127.0.0.1:{port}/config/model") as r:
                 out["model"] = await r.json()
     finally:
@@ -618,6 +621,14 @@ async def _serve():
 
 
 E = asyncio.run(_serve())
+_nl_words = json.load(io.open(os.path.join(HERE, "app", "ui_text", "nl.json"),
+                              encoding="utf-8"))["home_words"]
+check("UX-13 P5: /status?lang=nl-BE builds Home in Dutch, and plain /status "
+      "stays English",
+      E["status_nl"]["state"]["pill"] in _nl_words["pill"].values()
+      and E["status_nl"]["control"]["text"] in _nl_words["control"].values()
+      and E["status"]["state"]["pill"] not in _nl_words["pill"].values()
+      and set(E["status_nl"]) == set(E["status"]))
 check("GET / serves the assembled page as HTML", E["page"][0] == 200
       and E["page"][1] == "text/html" and E["page"][2] == PAGE)
 check("GET status over HTTP carries both halves",