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/alerts.service.ts

@@ -1,5 +1,5 @@
 /**
- * Phase B alert framework — service layer.
+ * Phase B alert framework - service layer.
  *
  * This is the skeleton: types, function shapes, and behaviour stubs. The
  * actual rule evaluators live in `alert-rules.ts` (PR2). The cron
@@ -46,7 +46,7 @@ export async function reconcileAlertsForPort(
   ruleId: AlertRuleId,
   candidates: AlertCandidate[],
 ): Promise<void> {
-  // Insert new / leave existing — only one open row per fingerprint
+  // Insert new / leave existing - only one open row per fingerprint
   // thanks to the partial unique index. Track newly inserted rows so we
   // can emit `alert:created` to the port room.
   for (const c of candidates) {