Home's admin-only KPI row lands, and every shortened figure carries its whole text in a title #2899

Replaces #2871. Pull #2878 (branch scout/2871-home-opens-with-a-kpi-row-in-studio-word) already builds the row, and the last reviews confirm the admin-only gate holds on / and in the terminal, tested through both. Two review points remain. Finish that pull rather than starting over.

Done looks like:

• [ ] tile() in src/web/studio/kpi_row.ts puts a title holding the full, untruncated text on every element whose text can be shortened (value and note). A test in test/home-kpis.test.ts fails without it.
• [ ] The README line about the row names src/flow/kpi_words.ts for kpiLines, not src/web/studio/kpi_row.ts.
• [ ] Unchanged and still tested: only an admin sees the figures, on Home and on the terminal dashboard; a non-admin and the lean first-steps home render no figures.
• [ ] The pull says Closes this issue.
• [ ] Before pushing: bun x tsc --noEmit and bun test test/home-kpis.test.ts test/studio-words.test.ts test/design-lint.test.ts.

Files: src/web/studio/kpi_row.ts, README.md, test/home-kpis.test.ts. Risks: a title must not bring back the words the studio check forbids (commit, merge, branch, repository, pull request). Brief: scout.