chore(style): codebase em-dash sweep + minor layout polish

Replaces every em-dash and en-dash with regular ASCII hyphens
across comments, JSX strings, and dev-facing logs. Mostly cosmetic
but stops the inconsistent mix that crept in over the last few
months (some files used em-dashes in comments, others didn't,
some used both).

Bundles two small dashboard-layout tweaks that touch a couple of
already-modified files:
- (dashboard)/layout.tsx main padding goes from p-6 to pt-3 px-6
  pb-6 so page content sits closer to the topbar.
- Sidebar now receives the ports list it needs for the footer
  port switcher.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/shared/page-header.tsx

@@ -21,7 +21,7 @@ interface PageHeaderProps {
  * existing call-sites stay unchanged.
  *
  * Mobile-aware: below sm (640px) the title/eyebrow/description/gradient
- * frame all collapse — the page title is already shown by the mobile topbar,
+ * frame all collapse - the page title is already shown by the mobile topbar,
  * so duplicating it in the body wastes scroll real estate. What remains is a
  * flush right-aligned action row (or nothing if there are no actions). On sm+
  * the full strip with title+description renders as before.
@@ -48,7 +48,10 @@ export function PageHeader({
       {/* Desktop: full strip with title, eyebrow, description, kpi line, actions. */}
       <div
         className={cn(
-          'hidden sm:flex flex-col gap-3 sm:mb-6 sm:flex-row sm:items-start sm:justify-between sm:gap-4',
+          // Removed `sm:mb-6` - the parent shell already provides
+          // appropriate gap-y between header and the next section, and the
+          // double-spacing produced an oversized top margin on dashboards.
+          'hidden sm:flex flex-col gap-3 sm:flex-row sm:items-start sm:justify-between sm:gap-4',
           isGradient &&
             'rounded-xl border border-slate-200 bg-gradient-brand-soft px-5 py-4 shadow-xs',
           className,