articles: auto-link company mentions to manufacturer directory

When an article body is rendered, scan it for any company name in
bb.tracked_companies (directory_visible=true) and wrap the first
mention of each company in
  <a class="company-mention" data-company-slug="...">Name</a>
linking to /manufacturers/<slug>. Caps at 12 mentions per article so
heavy press-release lists don't get visually noisy.

Match rules:
- Word-boundary, case-insensitive
- Skips text already inside <a>, <script>, <style>, code/pre/headings
- Skips any element with data-no-autolink="true"
- Longest name wins on overlap (Sony Pictures beats Sony)
- One link per company per article (first occurrence)

Hover behavior: a new CompanyMentionsHover client component mounts once
per article page, listens globally for [data-company-slug] hovers, and
pops a floating card showing logo, name, 2-sentence bio, sponsor/NAB/IBC
badges, HQ city, 3 recent stories, and links to the full profile +
external website. Preview data fetched from new endpoint
  /api/public/companies/[slug]/preview
with a client-side cache keyed by slug.

Includes non-advertisers — any visible directory entry gets linked,
which is the point. If a company is *also* a current banner advertiser
on broadcastbeat, the hover card adds a green "Sponsor" badge.

Styling: dotted underline that becomes solid on hover, slightly bolder
weight, accent color on hover. Subtle so multi-mention paragraphs don't
look like a link-soup.

src/styles/tailwind.css

@@ -591,6 +591,25 @@ h1, h2, h3 {
   color: var(--color-accent-dark);
 }
 
+/* Auto-linked company mentions (manufacturer directory cross-links).
+   Subtler than a generic link so they don't visually swamp the body copy
+   when several appear in one paragraph. */
+.article-body a.company-mention,
+a.company-mention {
+  color: #e0e0e0;
+  text-decoration: none;
+  border-bottom: 1px dotted var(--color-accent);
+  font-weight: 600;
+  cursor: help;
+  transition: color var(--transition-fast), border-color var(--transition-fast);
+}
+.article-body a.company-mention:hover,
+a.company-mention:hover {
+  color: var(--color-accent);
+  border-bottom-color: var(--color-accent);
+  border-bottom-style: solid;
+}
+
 .article-body blockquote {
   border-left: 3px solid var(--color-accent);
   padding-left: 1rem;