panel-redesign: Server pages and Help on the kit; the help drawer is gone

Stage 2, step 6. Written by Sonnet, reviewed by Opus.

  - Six pages named after their mockups: system-log, backup, users,
    user, user-delete, help, with typed page data (view/server.go,
    help.go), fixtures and tests. The old templates of the six are gone
    (user_form.html, encrypt_fields.html deleted, the others rewritten)
    and their names are off legacy_pages.txt, which now holds mail_queue
    alone.
  - Help is six help_topic blocks (checks, certificate, rdns, dns, apps,
    limits); a test renders every fixture page and fails on a Help link
    without a topic. The help drawer (help_drawer.html and its includes
    in layout_legacy.html) is removed; its rules in legacy.css go with
    the next step.
  - The user form sets the user's e-mail (plan, Account e-mail): create
    and update, validated, and a changed address resyncs DMARC for a
    user whose default is the account e-mail - through the helper the
    Account profile now shares.
  - Handlers pass typed data; routes, POST targets, field names,
    validation and authorization are unchanged. A test loads the user
    form for four reach combinations and for the only global user, posts
    it back untouched and finds the user unchanged.

Fixed on the way
  - The user delete confirmation said the domains were not affected. A
    domain that follows the user's default report address is left with
    none; the page names those domains now.
  - A refused backup lost the encryption choice and printed a literal
    <code> element in its message.

Differences from the mockups, for the owner:
  - Help has no DMARC and no Inbound topic: its outline fixes two boxes
    of three topics, although other mockups link to #dmarc and #inbound.
    Until the owner decides, Account's Help link goes to #dns and the
    inbound MX box has none;
  - system log: newest line first, as drawn; "refreshes on its own" (5 s
    active, 30 s idle); only status=, warning: and error: lines are
    coloured;
  - backup: the file field is a plain file input; the encryption box is
    ticked, as drawn and as on the domain export, so a plain download
    means unticking it first;
  - users: an E-mail column; the flash does not name the user;
  - user form: no lead; the domain lists are no longer hidden by script
    when Global is chosen (the server ignores them for that role).

Evidence
  - docs/assets/panel-redesign/evidence/system-log.png, backup.png,
    users.png, user.png, user-delete.png, help.png: 1440 px wide,
    headless Edge, real templates served locally with their fixtures -
    NOT from the container (no Docker on this machine).
  - panel/audit.js on the six pages at 1440 and 1280: 720 texts checked,
    problems: [].
  - The system log's polling swap was not exercised in a browser; it
    uses the mechanism of Overview and Health.
  - go test -count=1 ./internal/web/... ./cmd/panel
      ok  internal/web
      ok  internal/web/auth
      ok  internal/web/handlers
      ok  internal/web/validate
      ok  internal/web/view
      ok  cmd/panel

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

internal/web/view/view.go

@@ -32,9 +32,7 @@ type Engine struct {
 // from the component kit (kitPages); pages that embed a polling fragment
 // (architecture.md § Panel HTTP surface) list that fragment's file too, so the
 // same {{define}} block renders both the initial page and the fragment's own
-// refresh responses identically. Pages sharing a block of markup (the
-// encryption fields on the two secret downloads) list that partial the same
-// way.
+// refresh responses identically.
 var pageFiles = map[string][]string{
 	"setup":               {"templates/setup.html"},
 	"login":               {"templates/login.html"},
@@ -42,10 +40,12 @@ var pageFiles = map[string][]string{
 	"health":              {"templates/health.html", "templates/health_body.html"},
 	"account":             {"templates/account.html"},
 	"settings":            {"templates/settings.html"},
+	"system-log":          {"templates/system_log.html", "templates/system_log_body.html"},
+	"backup":              {"templates/backup.html"},
 	"users":               {"templates/users.html"},
-	"user_form":           {"templates/user_form.html"},
-	"user_delete":         {"templates/user_delete.html"},
-	"backup":              {"templates/backup.html", "templates/encrypt_fields.html"},
+	"user":                {"templates/user.html"},
+	"user-delete":         {"templates/user_delete.html"},
+	"help":                {"templates/help.html"},
 	"out-domains":         {"templates/out_domains.html"},
 	"out-domain":          {"templates/out_domain.html"},
 	"out-domain-settings": {"templates/out_domain_settings.html"},
@@ -61,8 +61,6 @@ var pageFiles = map[string][]string{
 	"dmarc-domain":        {"templates/dmarc_domain.html"},
 	"dmarc-report":        {"templates/dmarc_report.html"},
 	"mail_queue":          {"templates/mail_queue.html", "templates/mail_queue_body.html"},
-	"system_log":          {"templates/system_log.html", "templates/system_log_body.html"},
-	"help":                {"templates/help.html"},
 	"components":          {"templates/kit.html"},
 }
 
@@ -97,6 +95,13 @@ var kitPages = map[string]bool{
 	"dmarc":        true,
 	"dmarc-domain": true,
 	"dmarc-report": true,
+
+	"system-log":  true,
+	"backup":      true,
+	"users":       true,
+	"user":        true,
+	"user-delete": true,
+	"help":        true,
 }
 
 // fragmentFiles maps a fragment name (also its {{define}} block name) to its
@@ -110,7 +115,7 @@ var fragmentFiles = map[string]string{
 }
 
 // kitFragments are the fragments rendered with the component kit's partials.
-var kitFragments = map[string]bool{"health_body": true, "overview_poll": true, "out_log_rows": true}
+var kitFragments = map[string]bool{"health_body": true, "overview_poll": true, "out_log_rows": true, "system_log_body": true}
 
 // New parses embedded templates. version is stamped into every page footer.
 func New(version string) (*Engine, error) {
@@ -122,7 +127,7 @@ func New(version string) (*Engine, error) {
 	for name, files := range pageFiles {
 		// A page parses with the layout of its design. The template is named
 		// after the layout file so that its content is the layout's.
-		layout, shared := "layout_legacy.html", []string{"templates/help_drawer.html"}
+		layout, shared := "layout_legacy.html", []string(nil)
 		if kitPages[name] {
 			layout, shared = "layout.html", []string{"templates/components.html"}
 		}