feat: add featured/locked columns and auto-rotation logic to news pipeline

- Add `ai_grade`, `featured`, `featured_locked`, `landing_locked`, `author`, `article_published`, `image_url`, `has_unique_image` columns to news table
- Extend `news_images` schema with `alt_text`, `phash`, `width`, `height`, `is_placeholder` columns
- Create `idx_news_featured` index for efficient featured queries
- Update admin toggle endpoints to set `featured_locked`/`landing_locked` when manually toggling
- Propagate `featured` and `image_url` fields through landing page, news list, and detail page rendering
- Update `get_featured_news` to return `featured` and `image_url` fields
- Document in AGENTS.md the full zero-maintenance pipeline: image perceptual hashing, placeholder detection, AI grading on cleaned text, reliability gate, effective score computation, and post-loop landing rotation
- Update README.md service description to reflect automatic image comparison and landing rotation capabilities
- Clarify docs_api.py summaries that toggling featured/landing now locks articles from auto-rotation

devplacepy/static/css/news.css

@@ -98,6 +98,20 @@
     color: var(--warning);
 }
 
+.news-featured-badge {
+    font-size: 0.625rem;
+    font-weight: 700;
+    text-transform: uppercase;
+    letter-spacing: 0.05em;
+    padding: 0.125rem 0.5rem;
+    border-radius: 999px;
+    background: var(--accent);
+    color: var(--bg-primary);
+    display: inline-flex;
+    align-items: center;
+    gap: 0.25rem;
+}
+
 .news-time {
     font-size: 0.75rem;
     color: var(--text-muted);

devplacepy/static/css/services.css

@@ -307,6 +307,30 @@
     max-width: 70ch;
 }
 
+.service-detail-details {
+    margin: 0 0 0.75rem;
+    max-width: 80ch;
+    border: 1px solid var(--border);
+    border-radius: var(--radius);
+    background: var(--surface-2, var(--surface));
+    padding: 0.5rem 0.75rem;
+}
+
+.service-detail-details > summary {
+    cursor: pointer;
+    font-weight: 600;
+    color: var(--text-primary);
+    font-size: 0.875rem;
+}
+
+.service-detail-details-body {
+    white-space: pre-line;
+    color: var(--text-secondary);
+    font-size: 0.8125rem;
+    line-height: 1.5;
+    margin-top: 0.5rem;
+}
+
 /* ---- Tabs ---- */
 .svc-tabbar {
     display: flex;