inbound-antispam-panel: Inbound log, Why as a sheet; no Deny on a Postfix reject

Follows the two design commits before it (owner's decisions quoted
there).

Kit: a new component, Sheet / SheetRow (components.go), partials
sheet_tag and sheet (components.html), its rules in panel.css as in
theme.css, and its sample on the kit page next to status_tag. It is
the browser's popover: no script.

Inbound log: the Why column is gone; the decision tag opens a sheet
with who decided, then either the filter's verdict and its symbols one
a line (a detail the journal milter wrote) or the reply (a detail the
tailer read from mail.log - it starts with its code), and the subject
whole. The sheet's id is the journal row's. A row Postfix itself
refused no longer links to the filter lists.

Tests: the page fixture and view tests for the sheet's markup and
content (TestWhyRows), the link rule, three Deny and two Allow on the
mockup's six rows; e2e reads "Decided by" and "Reply" from the sheet
and wants no sender link on the refused row.

Seen: the fixture page with a sheet open, headless Edge at 1360 px -
the same as the accepted drawing.

Checked on the test server, uncommitted tree: go vet ./... ok,
go test ./... ok (22 packages), make e2e ok.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/web/view/kit.go

@@ -21,6 +21,7 @@ type Kit struct {
 	Postmarks     []Postmark
 	StatusTag     Box
 	StatusRows    []KitStatusRow
+	Sheet         Sheet
 	BoxHead       Box
 	BoxFoot       Foot
 	DangerZone    Box
@@ -91,6 +92,10 @@ func KitPage() *Kit {
 		},
 
 		StatusTag: Box{No: "03", Title: "status_tag", End: Plain("One mapping, one function")},
+		Sheet: Sheet{ID: "kit-sheet", Tag: Tag{Status: "reject"}, Title: "sheet", Rows: []SheetRow{
+			{Label: "What it holds", Lines: []string{"What does not fit the row, as name and value"}},
+			{Label: "How it closes", Lines: []string{"Esc", "a click outside", "the cross"}, Mono: true},
+		}},
 		StatusRows: []KitStatusRow{
 			{"ok, published, running, sent, accept", Tag{Status: "ok"}},
 			{"warn, deferred, quiet, tempfail", Tag{Status: "warn"}},