refactor(ts-migration): Phase 11 batch 11 — the data pages

The last nine admin pages. `src/` now contains no `.js` or `.jsx` at all.

One error, and it was the same kind of thing the whole phase has been
finding: `getBandMembers(min, max)` in `TalentPool` is called with one
argument for the top band, and its own body reads
`max == null || s < max`. The parameter has always been optional
everywhere except the signature. The marker erases.

9/9 byte-identical, and the bundle still hashes to 74d17e2d…

Three of these nine — `Analytics`, `Candidates`, `HiredHistory` — are
the pages the Owliver baselines cover, and they carry six of the seven
pre-existing suite failures. Those failures are unchanged and still match
`ecf5e75` line for line, which is the point: if a rename had altered what
these pages render, it would have altered how they fail, and it did not.
The baselines are untouched, as they have been in every batch.

Phase 11 is 122/122 files and eleven batches. Across all of them:

  type erasure  122/122 byte-identical
  bundle        74d17e2d… unchanged from `ecf5e75` in every batch
  npm test      1684/1691 with the same 7 failures, in every batch
  typecheck     20 errors at the start, 6 now

The remaining 6 all pre-date the migration. They are no longer in
JavaScript, so they are now fixable; that is the next commit, not this
one.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HBG1wnuRfJKCstGB8Fekr8

src/pages/admin/TalentPool.tsx

@@ -73,7 +73,7 @@ export default function AdminTalentPool() {
   };
 
   const segments = useMemo(() => {
-    const getBandMembers = (min, max) => profiles.filter((p) => {
+    const getBandMembers = (min, max?) => profiles.filter((p) => {
       const s = p.krow_score || 0;
       return s >= min && (max == null || s < max);
     });