feat: add AI markdown reformatting and usage metering to NewsService

Add AI-powered body reformatting for valid articles in the news pipeline, converting raw text walls into clean Markdown with paragraphs, headings, and lists. Introduce `news_usage` database table and `add_news_usage`/`get_news_usage` helpers to track per-cycle gateway costs (calls, tokens, latency, USD) from response headers, reported on the admin Services page. Remove unused `.sidebar-more` CSS and apply `render_title()` to poll question/label fields.

devplacepy/static/css/sidebar.css

@@ -82,34 +82,6 @@
     box-shadow: var(--glow-accent);
 }
 
-.sidebar-more {
-    display: flex;
-    flex-direction: column;
-    gap: 0.125rem;
-}
-
-.sidebar-more-toggle {
-    list-style: none;
-    cursor: pointer;
-    user-select: none;
-}
-
-.sidebar-more-toggle::-webkit-details-marker {
-    display: none;
-}
-
-.sidebar-more-chevron {
-    margin-left: auto;
-    font-size: 1rem;
-    line-height: 1;
-    color: var(--text-muted);
-    transition: transform 0.15s ease;
-}
-
-.sidebar-more[open] > .sidebar-more-toggle .sidebar-more-chevron {
-    transform: rotate(90deg);
-}
-
 .sidebar-dot {
     width: 8px;
     height: 8px;