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/clients.ts

@@ -127,7 +127,7 @@ export const clientTags = pgTable(
     clientId: text('client_id')
       .notNull()
       .references(() => clients.id, { onDelete: 'cascade' }),
-    tagId: text('tag_id').notNull(), // references tags.id — defined later in system.ts
+    tagId: text('tag_id').notNull(), // references tags.id - defined later in system.ts
   },
   (table) => [primaryKey({ columns: [table.clientId, table.tagId] })],
 );
@@ -194,7 +194,7 @@ export const clientMergeCandidates = pgTable(
   },
   (table) => [
     index('idx_cmc_port_status').on(table.portId, table.status),
-    // Same pair shouldn't surface twice — enforce uniqueness on the
+    // Same pair shouldn't surface twice - enforce uniqueness on the
     // canonical (a < b) ordering.
     uniqueIndex('idx_cmc_pair').on(table.portId, table.clientAId, table.clientBId),
   ],