feat(approvals): make the inbox opt-in (default OFF) and drop em-dashes

Owner decision: every Approvals Inbox UI surface (header bell, drawer,
phone overview answer strips, reload seeding) now requires enabling
approvalsInboxEnabled in App Settings -> Panels; only an explicit true
turns it on. The store, endpoints, and push Approve/Deny actions keep
running regardless (the push buttons are already opt-in per subscription).

Also replaces em-dashes with plain punctuation across the newly authored
comments, docs, and strings.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/web/public/sw.js

@@ -159,7 +159,7 @@ self.addEventListener('notificationclick', (event) => {
         body: JSON.stringify({ action }),
       }).then((res) => {
         if (res && res.ok) return undefined;
-        // 401/404/409: let the human see the state — fall back to a tab.
+        // 401/404/409: let the human see the state by falling back to a tab.
         return openOrFocus(sessionId, action, approvalId, targetUrl);
       }).catch(() => openOrFocus(sessionId, action, approvalId, targetUrl))
     );