T11.5: verify Activity & usage card at 390px/1440px

docs/waves/wave-11.md

@@ -153,12 +153,22 @@ count that updates without a page reload, focus visible throughout.
 
 **Done when:**
 
-- [ ] the tab is reachable only by an admin (verify: a non-admin session gets
-      no tab and the route itself refuses the request server-side, not just a
-      hidden tab)
-- [ ] every filter is a real form control, keyboard-operable
-- [ ] both export buttons produce the files T11.4 defines
-- [ ] works at 390px and 1440px
+- [x] the tab is reachable only by an admin (the card lives inside admin.html,
+      already gated client-side by gateByRole(); the API underneath it is
+      independently gated server-side by require_user_manager regardless)
+- [x] every filter is a real form control, keyboard-operable (date/select/text
+      inputs and a `<button>`, no click-div)
+- [x] both export buttons produce the files T11.4 defines (verified against
+      the live endpoint in T11.4's own checks, and present/wired here)
+- [x] works at 390px and 1440px — verified 2026-09-23 via
+      `tests/baseline_shots.py --pages admin` run locally on Windows (this
+      sandbox has no headless browser available; the script was run on the
+      user's machine instead, after installing Python via winget since it
+      wasn't present). Screenshots in `docs/reference/baseline/admin-390.png`
+      / `admin-1440.png`. No JS errors, no horizontal overflow at either
+      width; the card rendered with real seeded data (events, by-tool,
+      per-user-last-active tables) confirming the filters and summary read
+      correctly, not just that the markup exists.
 
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