[FRONTEND] Section arrows and See all pages — pin the back arrow, add Upcoming, enlarge hit targets

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Two testers independently flagged the dashboard section arrows and the pages behind them. The hit-target complaint is the sharp one — a tester reported missing the arrow two times out of three.

Reports

• "The arrow in the top-left corner currently slides up when the screen is scrolled, but it should remain fixed in place... there is no arrow for the Upcoming section, which makes the UI feel inconsistent. The arrows are also quite small and could be increased in size... When the arrows are clicked and all the related events are displayed on a separate page, the event cards appear aligned too much to one side, which makes the page look visually unbalanced." — Devanshi Patel, iPhone 14 Pro, iOS 26.6.1
• "Arrow hit boxes are very small, I miss it 2/3 times" — Anonymous, iPhone 16 Pro Max, iOS 27.0

Fix

• Pin the top-left back arrow to the header so it stays put while the content scrolls
• Add the missing section arrow to Upcoming so every section behaves the same
• Increase the arrow hit target to at least 44×44pt — the visual glyph can stay small, the touchable area shouldn't
• Centre the event cards on the See all page with consistent gutters

Notes

• [FRONTEND] Home page bug sweep — going/save state, notifications, and visuals #397 already covers replacing the ">" with a burnt orange "See all >" and the single-column card drop on the category view — coordinate so the arrow work and the label work don't collide. Do not redo either item here.
• A tester on iPhone 16 Pro Max separately asked "Maybe this should be a grid but it's showing as a 1x1 list?" — that's the same single-column bug already tracked in [FRONTEND] Home page bug sweep — going/save state, notifications, and visuals #397.

[linear]

LOOP-283