Break long values on the webhook page and event log at phone width (closes #391)

A name, ID or content type with no place to break ran past its row and
was cut off by the card at 390 pixels, and a long webhook name made the
webhook page scroll sideways. The elements holding such values now
carry wrap-anywhere, so a value breaks only where it must; controls,
statuses and times never do, so a row too wide for a phone still runs
past the edge. The event log's title row wraps like the webhook page's.

The browser test gains a 390-pixel check of both pages: neither scrolls
sideways and nothing shown runs past the page's or its card's edge. Its
seeded webhook name and newer event's content type are long enough to
fail without the change.

Model: opus-5-5

README.md

@@ -1280,7 +1280,9 @@ the event log only the newest starts expanded, and an event there expands and
 collapses when its row's caret or its ID is clicked, and from the keyboard, but
 not when its ID is selected with the mouse, and a delivery's attempts inside it
 expand and collapse; and at phone width the menu button opens and closes the
-mobile menu. It also fails if the browser reports a console warning or error, an
+mobile menu, and neither the webhook page nor the event log, with a delivery's
+attempts open, scrolls sideways or cuts anything off at the page's or a card's
+edge. It also fails if the browser reports a console warning or error, an
 uncaught exception, or anything the policy refused. `make check` and the image
 build lint it but do not run it, and `make test` leaves it out (its file is
 built only with the `browser` build tag). Run it with `make test-browser` after