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

An event's ID or content type, or a name 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. Both pages' outer
containers now carry wrap-anywhere, so such a value breaks only where
it must; 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

internal/handlers/source_detail_test.go

@@ -251,8 +251,9 @@ func TestHandleSourceDetail_RendersNamedTargetFields(
 // page's maximum width at 108rem (1728 px), half again the 72rem of
 // max-w-6xl that the webhook list and the event log use, so an
 // entrypoint URL fits on one line in a 1920-pixel window; and the
-// wrapping of its title row, so the buttons beside the title do not
-// push a phone-width window into scrolling sideways.
+// wrapping of its title row and of long values, so neither the buttons
+// beside the title nor a long name push a phone-width window into
+// scrolling sideways.
 func TestHandleSourceDetail_FitsWideAndNarrowWindows(t *testing.T) {
 	t.Parallel()
 
@@ -273,7 +274,7 @@ func TestHandleSourceDetail_FitsWideAndNarrowWindows(t *testing.T) {
 
 	assert.Contains(
 		t, body,
-		`<div class="mx-auto px-6 py-8" style="max-width: 108rem"`,
+		`<div class="mx-auto px-6 py-8 wrap-anywhere" style="max-width: 108rem"`,
 	)
 	assert.Contains(
 		t, body,