panel-redesign: paths follow the menu; Account and Server settings split

Stage 1, step 3 (plan § Routes). BREAKING: every panel URL changes and the
old paths are removed without redirects.

Routes (web.go)
  - /status -> /overview; /domains -> /outbound/domains with the domain's
    settings actions under .../settings/ (reports, ratelimit, export);
    /deliveries -> /outbound/log; /mail-queue -> /outbound/queue; /dmarc ->
    /outbound/dmarc; /inbound -> /inbound/domains; /system-log ->
    /server/log; /backup -> /server/backup (import under it); /users ->
    /server/users; recheck and reload under /server/health/.
  - One fragment name: <page>/fragment everywhere.
  - Everything under /server/ is registered through server(), which wraps
    the handler in globalOnly: the subtree is guarded once, where a new
    route cannot forget it. Handlers keep their own requireGlobal.
  - GET / leads to /overview, /outbound/domains or /inbound/domains.
  - The /account -> /settings redirect is gone with /settings.

Account and Server > Settings
  - handlers_account.go: GET /account and three POSTs - profile (username,
    e-mail; no password asked, as designed), password (current password,
    rate-limited like a sign-in, signs out other sessions), dmarc (the
    user's default: hosted / account / custom / none, each validated).
    This replaces step 1's bridge through the old Settings form.
  - handlers_settings.go is the instance's page only: log retention and the
    read-only rate limits, global role.
  - One legacy template serves both pages by a flag until stage 2 gives each
    its own: a new legacy page cannot be added to the ratchet.

Still to come inside stage 1, and why @routes stays on the ratchet:
  - step 4: the application routes (one POST, under the domain);
  - step 5: GET /server/health.
With @routes removed by hand TestRoutesFollowNavigation reports exactly
those and nothing else - no template links to a path the router lacks.

Old templates, tests and the e2e client are retargeted. The e2e module was
edited but not run here (no Docker, and its dependency could not be
downloaded on this machine).

Tests: Account (page, profile, password, DMARC default in every mode, a
domain administrator's own row only), Server settings (saved without a
password, range, global only), the /server/ subtree answered 404 by the
router for a domain administrator with All on both lists and for no
principal.

go test ./...  green except the two Windows-only failures in internal/domain
and internal/logtail.

Roadmap 13/27.

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

internal/web/view/templates/settings.html

@@ -1,86 +1,119 @@
-{{/* Wide enough for credentials and DMARC settings side by side (see .split
-     in panel.css, as on a delivery's page). */}}
+{{/* One legacy template for two pages until stage 2 gives each its own:
+     Account (GET /account, every role) — the user's name and e-mail, their
+     password and their default DMARC report address, each its own form — and
+     Server › Settings (GET /server/settings, global role) — what holds for the
+     whole instance. .AccountPage says which one this is. */}}
 {{define "wide"}}wide{{end}}
 
-{{/* The username/password fields are identical for a global administrator
-     (split card, DMARC alongside) and a domain administrator (narrow card,
-     no DMARC card) — only the surrounding form and card differ. */}}
-{{define "credentials_fields"}}
-<label for="username">Username</label>
-<input id="username" name="username" autocomplete="username"
-       autocapitalize="none" spellcheck="false" value="{{.FormUsername}}" required>
-
-<label for="current_password">Current password</label>
-<input id="current_password" name="current_password" type="password"
-       autocomplete="current-password" required>
-
-<label for="new_password">New password</label>
-<input id="new_password" name="new_password" type="password" autocomplete="new-password">
-
-<label for="new_password_confirm">Confirm new password</label>
-<input id="new_password_confirm" name="new_password_confirm" type="password" autocomplete="new-password">
-{{end}}
-
 {{define "content"}}
-<h1>Settings</h1>
+{{if .AccountPage}}
+<h1>Account</h1>
 
 {{if .Flash}}<div class="flash">{{.Flash}}</div>{{end}}
 {{if .Error}}<p class="error">{{.Error}}</p>{{end}}
 
-{{if .ShowDMARC}}
-<form method="post" action="/settings">
 <div class="split">
-  <div class="card">
-    <h2>Panel credentials</h2>
-    <p class="muted">These are the credentials for this control panel only.
-    Applications keep their own logins and passwords, which are not affected.</p>
+  <div class="card" id="profile">
+    <h2>Profile</h2>
+    <p class="muted">Signed in as {{.User}} · {{.Role}}. These are the
+    credentials for this control panel only. Applications keep their own logins
+    and passwords, which are not affected.</p>
+    <form method="post" action="/account/profile">
+      <label for="username">Username</label>
+      <input id="username" name="username" autocomplete="username"
+             autocapitalize="none" spellcheck="false" value="{{.FormUsername}}" required>
 
-    {{template "credentials_fields" .}}
+      <label for="email">E-mail</label>
+      <input id="email" name="email" type="email" autocomplete="email"
+             autocapitalize="none" spellcheck="false" value="{{.FormEmail}}">
+      <p class="muted">Where the panel writes to you. It can also receive DMARC
+      reports — your choice, under DMARC reports.</p>
+
+      <button type="submit">Save profile</button>
+    </form>
   </div>
 
-  <div class="card">
-    <h2>DMARC aggregate reports</h2>
-    <p class="muted">Optional default <code>rua=</code> address for every sending
-    domain (can be overridden per domain).{{if .DMARCIngestEnabled}} When set to
-    an address on <code>{{.HostedReportAddress}}</code>, SelfPost receives and
-    parses aggregate reports on port&nbsp;25.{{else}} Use a mailbox on a domain
-    that receives inbound mail elsewhere.{{end}}</p>
+  <div class="card" id="password">
+    <h2>Password</h2>
+    <form method="post" action="/account/password">
+      <label for="current_password">Current password</label>
+      <input id="current_password" name="current_password" type="password"
+             autocomplete="current-password" required>
 
-    <label for="dmarc_report_email">Default report address</label>
-    <input id="dmarc_report_email" name="dmarc_report_email" type="email"
-           autocomplete="email" autocapitalize="none" spellcheck="false"
-           value="{{.FormDMARCEmail}}" placeholder="{{if .DMARCIngestEnabled}}{{.HostedReportAddress}}{{else}}reports@your-mail-domain.com{{end}}">
+      <label for="new_password">New password</label>
+      <input id="new_password" name="new_password" type="password" autocomplete="new-password" required>
 
-    {{if .FormDMARCEmail}}
-    <p class="muted">When <code>rua=</code> points at another domain, that hub
-    domain must publish a report-authorisation record so receivers will deliver
-    the XML aggregates.</p>
+      <label for="new_password_confirm">Repeat</label>
+      <input id="new_password_confirm" name="new_password_confirm" type="password" autocomplete="new-password" required>
 
-    <label>Report authorization — host / name</label>
-    <div class="code-row">
-      <span class="code">{{.ReportAuthName}}</span>
-      <button type="button" class="copy">Copy</button>
-    </div>
-
-    <label>Report authorization — value</label>
-    <div class="code-row">
-      <span class="code">{{.ReportAuthExample}}</span>
-      <button type="button" class="copy">Copy</button>
-    </div>
-
-    {{if .ReportAuthDNS.Status}}
-    <label>Report authorization DNS <span class="st st-{{.ReportAuthDNS.Status}}">{{.ReportAuthDNS.Status}}</span></label>
-    <p class="{{if eq .ReportAuthDNS.Status "ok"}}muted{{else}}error{{end}}">{{.ReportAuthDNS.Detail}}</p>
-    {{if .ReportAuthDNS.Records}}<span class="code">{{range .ReportAuthDNS.Records}}{{.}}
-{{end}}</span>{{end}}
-    {{end}}
-    {{end}}
+      <button type="submit">Change password</button>
+    </form>
+    <p class="muted">Changing it signs out every other session of this account;
+    this one stays signed in.</p>
   </div>
 </div>
 
+<div class="card" id="dmarc">
+  <h2>DMARC reports</h2>
+  <p class="muted">Your default report address. It is used by every outbound
+  domain whose report address is set to follow your default; changing it
+  changes the DMARC record those domains must publish.</p>
+  <form method="post" action="/account/dmarc">
+    <label for="dmarc_default">My default report address</label>
+    <select id="dmarc_default" name="dmarc_default" data-custom-mode="custom">
+      {{if .DMARCIngestEnabled}}<option value="hosted"{{if eq .FormDMARCMode "hosted"}} selected{{end}}>SelfPost hosted — read them under DMARC</option>{{end}}
+      <option value="account"{{if eq .FormDMARCMode "account"}} selected{{end}}>My account e-mail{{if .AccountEmail}} — {{.AccountEmail}}{{end}}</option>
+      <option value="custom"{{if eq .FormDMARCMode "custom"}} selected{{end}}>Another address…</option>
+      <option value="none"{{if eq .FormDMARCMode "none"}} selected{{end}}>No reports</option>
+    </select>
+    <div data-custom-address>
+      <label for="dmarc_default_address">Report address</label>
+      <input id="dmarc_default_address" name="dmarc_default_address" type="email"
+             autocomplete="off" autocapitalize="none" spellcheck="false"
+             value="{{.FormDMARCAddress}}" placeholder="reports@your-mail-domain.com">
+    </div>
+    <button type="submit">Save report address</button>
+  </form>
+
+  {{if .ReportAuthName}}
+  <p class="muted">When <code>rua=</code> points at another domain, that hub
+  domain must publish a report-authorisation record so receivers will deliver
+  the XML aggregates.</p>
+
+  <label>Report authorization — host / name</label>
+  <div class="code-row">
+    <span class="code">{{.ReportAuthName}}</span>
+    <button type="button" class="copy">Copy</button>
+  </div>
+
+  <label>Report authorization — value</label>
+  <div class="code-row">
+    <span class="code">{{.ReportAuthExample}}</span>
+    <button type="button" class="copy">Copy</button>
+  </div>
+
+  {{if .ReportAuthDNS.Status}}
+  <label>Report authorization DNS <span class="st st-{{.ReportAuthDNS.Status}}">{{.ReportAuthDNS.Status}}</span></label>
+  <p class="{{if eq .ReportAuthDNS.Status "ok"}}muted{{else}}error{{end}}">{{.ReportAuthDNS.Detail}}</p>
+  {{if .ReportAuthDNS.Records}}<span class="code">{{range .ReportAuthDNS.Records}}{{.}}
+{{end}}</span>{{end}}
+  {{end}}
+  {{end}}
+</div>
+{{else}}
+<h1>Settings</h1>
+
+<p class="muted">What holds for the whole instance, whoever is signed in. Your
+own name, e-mail, password and DMARC report address are under
+<a href="/account">Account</a>.</p>
+
+{{if .Flash}}<div class="flash">{{.Flash}}</div>{{end}}
+{{if .Error}}<p class="error">{{.Error}}</p>{{end}}
+
+<form method="post" action="/server/settings">
 <div class="card" id="deliveries-retention">
   <h2>Deliveries</h2>
-  <p class="muted">How long rows on <a href="/deliveries">Deliveries</a> are
+  <p class="muted">How long rows on <a href="/outbound/log">Deliveries</a> are
   kept before the background sweep deletes them — the main driver of
   <code>/data</code> growth over time. Does not affect <code>mail.log</code>
   rotation (fourteen daily files).</p>
@@ -89,28 +122,9 @@
   <input id="send_log_retention_days" name="send_log_retention_days" type="number"
          min="7" max="365" step="1" required
          value="{{.FormSendLogRetentionDays}}">
+  <button type="submit">Save settings</button>
 </div>
-
-<button type="submit">Save changes</button>
-<p class="muted">Leave both new-password fields empty to change the username,
-DMARC address, or send log retention only. Changing the password signs out
-every other session; this one stays signed in.</p>
 </form>
-{{else}}
-<div class="card narrow">
-  <h2>Panel credentials</h2>
-  <p class="muted">These are the credentials for this control panel only.
-  Applications keep their own logins and passwords, which are not affected.</p>
-  <form method="post" action="/settings">
-    {{template "credentials_fields" .}}
-
-    <button type="submit">Save changes</button>
-  </form>
-  <p class="muted">Leave both new-password fields empty to change the username
-  only. Changing the password signs out every other session;
-  this one stays signed in.</p>
-</div>
-{{end}}
 
 <div class="card" id="rate-limits">
   <h2>Sending rate limits</h2>
@@ -135,3 +149,4 @@ every other session; this one stays signed in.</p>
   allow-list.</p>
 </div>
 {{end}}
+{{end}}