chore: one changeset for the release, and no new em-dashes

Consolidates the four contributor changesets, and rewords the em-dashes this release
added in comments and docs. The five in test/settings-save-failure-ui.test.ts stay:
they assert existing toast text.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

test/mocks/mock-session.ts

@@ -101,7 +101,7 @@ export class MockSession extends EventEmitter {
   /** The per-session CLAUDE_CONFIG_DIR override that Session.claudeConfigDir() reads. */
   claudeConfigDirOverride: string | undefined = undefined;
 
-  /** Mirrors Session.claudeConfigDir — the override, trimmed; undefined when unset. */
+  /** Mirrors Session.claudeConfigDir: the override, trimmed; undefined when unset. */
   claudeConfigDir(): string | undefined {
     return this.claudeConfigDirOverride?.trim() || undefined;
   }