Task: Document currency domain knowledge in the manual

Bring doc/manual/user_guide/chapter_5_currencies.org's Currency Details section back in sync with the app once the four tabs are restored — its prose already describes the four-tab structure correctly (it was never updated when codegen collapsed it to one tab), but its screenshots are stale and one tab has no screenshot at all.

• [X] assets/images/currency_details_{general,formatting,provenance}.png captions marked [SCREENSHOT OUTDATED — retake needed] in chapter 5 (they currently show the old hand-written dialog's chrome, not the restored view_group-based one).
• [X] assets/images/currency_details_rounding.png (existed as an asset, never embedded) now embedded in the *** Rounding subsection — a pre-existing gap, not caused by codegen — also marked outdated since it's the same stale pre-codegen image.
• [X] All four screenshots actually retaken against the live, regenerated dialog, cropped to just the dialog window, and captions restored to normal, via Retake currency detail dialog screenshots for the manual — 5/5 steps PASSED.
• [X] Chapter 5's prose re-verified field-by-field against the live dialog (labels, placeholder text, widget types, example values for AOA) — accurate, no changes needed.
• [X] Manual PDF rebuilt (compass build --direct deploy_manual) and confirmed: table of contents shows all four Currency Details tab sections (8.2 General, 8.3 Formatting, 8.4 Rounding, 8.5 Provenance — the Rounding entry didn't exist in the TOC before this task).

1. Marked all four Currency Details screenshot captions per the doc-update-manual skill's convention ([SCREENSHOT OUTDATED — retake needed]), including newly embedding the previously-unused Rounding screenshot asset.
2. Created a test_scenario (Retake currency detail dialog screenshots for the manual) that uses the QA Validation Runner's screenshot-capture feature (a sibling task in the QA Validation Runner story, merged to main since this story's scaffold task) — one step per tab, switching the currency dialog to that tab and clicking the step's own Screenshot button, plus a final non-live step for moving the captured files into assets/images/ and flipping the captions back to normal.
3. Run that scenario, then re-read chapter 5's prose against the live dialog while the screenshots are fresh.

Manual QA scenarios (scaffolded via compass add test_scenario, run through the QA Validation Runner panel) that verify this task. Link new ones here as they're created; the scenario doc itself links back via its "Verifies task" field.

Chapter 5's Currency Details section is back in sync with the app: all four tabs have current, correctly-cropped screenshots (including the Rounding tab, embedded for the first time), captions restored to normal, prose re-verified accurate, and the manual PDF rebuilds clean with the Rounding tab now appearing in the table of contents.