audit 4: log paging at its edges, NaN refused, a red rate limit, recalculation asks, reload writes all

Step 4 of stage 4 (L10, L11, L13, L18, L19 and a row of
review-2026-08-followups):

- The Outbound log counts first and clamps the page to the last; a number
  too large for an int (strconv's ErrRange with the largest int) is the
  last page on both logs. Tested at the edges: first, last, past the last
  however far, nonsense, an empty log asked for page 5.
- checkAutoMultiplier is "not within", so NaN and the infinities are out.
- rate-limited is red (components.go; the mockup first, 643892a).
- data-unsaved on both recalculate buttons: panel.js asks on submit
  (ev.submitter) when a field of the page differs from what it was drawn
  with; testdata/unsaved_test.js under TestPanelJS.
- HandleReload writes what a restore's first start writes - the filter
  lists and the DMARC maps too - and a failed step is an error flash on
  Health that names it, not plain text; the success flash says what was
  written.

Tested on the test server: go vet + go test of 25 packages, make e2e (all
pass, 695 s) on this tree.

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

internal/web/handlers/handlers_inbound_log_test.go

@@ -229,6 +229,8 @@ func TestInboundLogPages(t *testing.T) {
 	// A page past the end, or nonsense, is the last page, or the first.
 	has(t, "page 9", s.get(s.h.HandleInboundLog, "/inbound/log?domain=a.example.com&p=9", globalPrincipal).Body.String(), `Page 2 of 2`, `Hello A`)
 	has(t, "page x", s.get(s.h.HandleInboundLog, "/inbound/log?domain=a.example.com&p=x", globalPrincipal).Body.String(), `Page 1 of 2`)
+	has(t, "page huge", s.get(s.h.HandleInboundLog, "/inbound/log?domain=a.example.com&p=99999999999999999999", globalPrincipal).Body.String(), `Page 2 of 2`, `Hello A`)
+	has(t, "page 0", s.get(s.h.HandleInboundLog, "/inbound/log?domain=a.example.com&p=0", globalPrincipal).Body.String(), `Page 1 of 2`)
 }
 
 func TestInboundLogEmptyAndOff(t *testing.T) {
@@ -237,6 +239,9 @@ func TestInboundLogEmptyAndOff(t *testing.T) {
 	body := s.get(h.HandleInboundLog, "/inbound/log", globalPrincipal).Body.String()
 	has(t, "empty log", body, `No messages logged yet.`)
 	lacks(t, "empty log", body, `<table`, `Page 1`)
+	body = s.get(h.HandleInboundLog, "/inbound/log?p=5", globalPrincipal).Body.String()
+	has(t, "empty log, page 5", body, `No messages logged yet.`)
+	lacks(t, "empty log, page 5", body, `<table`, `Page `)
 
 	h.cfg.InboundEnabled = false
 	if rec := s.get(h.HandleInboundLog, "/inbound/log", globalPrincipal); rec.Code != http.StatusNotFound {