feat(career): practice invitations — closest stamps + bring-these-up (#953)

* feat(career): practice invitations — closest stamps + bring-these-up

Career v3, WS1. The passport now points at the practice that pays:

- Stubs carry next_star_at (the same primitive _stars() uses) and each
  passport exposes `nearest`: the top 3 non-qualifying songs by distance
  to their next star, in the worklist order.
- "Closest stamps" strip above the shelf: the in-progress graded
  passports nearest to minting, each row naming the ask — N more songs
  (with the nearest title + best %) or the blocking Virtuoso drill.
  Rows open the passport.
- "Bring these up" list on the stubs page of in-progress passports;
  earned pages stay memorabilia (no homework on a won badge).
- Invitation-voiced throughout: no meters, no completion pressure.

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

* docs(test): comment says qualifying-bar ranking, matching the assertion

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

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

plugins/career/screen.html

@@ -29,6 +29,7 @@
     <div id="career-tab-passports" class="hidden" role="tabpanel" aria-labelledby="career-tab-btn-passports">
         <p class="text-sm text-gray-400 mb-4">Commit to an instrument, pick a genre, and stamp your way to its badge — five ★★ songs mint a Bronze. Your passport wall is who you are as a musician.</p>
         <div id="pp-instruments" class="pp-instruments"></div>
+        <div id="pp-closest" class="mt-4"></div>
         <div id="pp-shelf-wrap" class="mt-5">
             <div id="pp-shelf" class="pp-shelf"></div>
         </div>