fix(observability): serve CSS from Flask static path

scripts/check_observability_ui.py

@@ -44,6 +44,7 @@ OBSERVABILITY_NAV_ITEMS = [
 ]
 
 CSS_PATH = Path("static/css/observability-system.css")
+WEB_CSS_PATH = Path("web/static/css/observability-system.css")
 SHELL_PATH = Path("templates/components/_ewoooc_shell.html")
 BASE_PATH = Path("templates/ewoooc_base.html")
 ROUTE_PATH = Path("routes/admin_observability_routes.py")
@@ -192,6 +193,18 @@ def scan_css() -> list[str]:
         if snippet not in text:
             findings.append(f"{CSS_PATH}: missing required token/class `{snippet}`")
 
+    web_path = ROOT / WEB_CSS_PATH
+    if not web_path.exists():
+        findings.append(
+            f"{WEB_CSS_PATH}: missing mirrored CSS served by Flask static route"
+        )
+    else:
+        web_text = web_path.read_text(encoding="utf-8")
+        if web_text != text:
+            findings.append(
+                f"{WEB_CSS_PATH}: must match {CSS_PATH} so production /static CSS is in sync"
+            )
+
     return findings