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/db/schema/ai-usage.ts

@@ -7,7 +7,7 @@
  * soft warnings and hard caps.
  *
  * Token-denominated rather than dollar-denominated so the cap survives
- * model price changes — and it's the unit both OpenAI and Anthropic
+ * model price changes - and it's the unit both OpenAI and Anthropic
  * SDKs return in `response.usage`.
  */
 
@@ -25,7 +25,7 @@ export const aiUsageLedger = pgTable(
     portId: text('port_id')
       .notNull()
       .references(() => ports.id, { onDelete: 'cascade' }),
-    /** Optional — system-initiated calls (e.g. scheduled summarizers) won't have a user. */
+    /** Optional - system-initiated calls (e.g. scheduled summarizers) won't have a user. */
     userId: text('user_id').references(() => user.id, { onDelete: 'set null' }),
     /** Stable feature key: 'ocr', 'summary', 'embedding', 'reply_draft', etc. */
     feature: text('feature').notNull(),