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/lib/services/alert-engine.ts

@@ -1,5 +1,5 @@
 /**
- * Alert engine — runs every rule against every port. Called by the
+ * Alert engine - runs every rule against every port. Called by the
  * BullMQ recurring job 'alerts-evaluate' every 5 minutes; exposed as a
  * function so integration tests can drive it without a worker.
  */