Coaching card: clarify sessions are ongoing, not one-and-done

Inga's review flagged that "Booked in single sessions" read as a single
total session. Reword to "one session at a time — as many as the work
calls for" so the individually-booked-but-ongoing nature is clear.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

index.html

@@ -129,7 +129,7 @@
         <article class="card">
           <p class="card-tag">Coaching · succession</p>
           <h3>The people at the center</h3>
-          <p>One-to-one coaching for the people carrying the weight: the owner planning his exit, the successor stepping into big shoes, the veteran working out what it means to let go. Booked in single sessions, around your calendar.</p>
+          <p>One-to-one coaching for the people carrying the weight: the owner planning his exit, the successor stepping into big shoes, the veteran working out what it means to let go. Booked one session at a time — as many as the work calls for — around your calendar.</p>
           <p class="outcome">The people at the center don't crack under it.</p>
         </article>
       </div>