Setup and invitations: the first login made from the client, everyone else by a group's invitation

PrivaPub's sign-up is closed. While it has no administrator, Login offers /setup, where the first login is made with its
first persona and becomes the administrator (PrivaPub's /clientapi/user/setup; owner decision 2026-10-16: first come,
first served, and setup then closes for good). Everyone else joins at /join?code=: a group's invitation makes the login,
and its first persona joins the group (/clientapi/user/invitation/signup). Login links there, and a group's page shows
the link next to its code. A login without a persona is sent from Login to Settings instead of a dead end. Login, setup
and join share AuthService's StartSession, and all three go without credentials.

e2e (Login/SignUpTests, against the pasture): setup offered on Login, made, the feed reached with Administration, then a
signed-out reader is offered sign-in and invitations only; an invitation link makes a login whose persona joins the
circle. The phone sweep covers /setup and /join: login, setup and join fit every portrait phone, and AccountTests signs
in through the changed Login. The town's signed-in tests were not rerun: today's pasture came up without Mastodon, and
its town seed left stale sessions.

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

Resources/AllStrings.resx

@@ -425,9 +425,6 @@
   <data name="This device did not give its position: {0}" xml:space="preserve">
     <value>This device did not give its position: {0}</value>
   </data>
-  <data name="This login has no persona to act as. Create one on PrivaPub first." xml:space="preserve">
-    <value>This login has no persona to act as. Create one on PrivaPub first.</value>
-  </data>
   <data name="This persona is in no community or circle yet." xml:space="preserve">
     <value>This persona is in no community or circle yet.</value>
   </data>
@@ -2246,4 +2243,67 @@
   <data name="servers blocked" xml:space="preserve">
     <value>servers blocked</value>
   </data>
+  <data name="Set up PrivaPub" xml:space="preserve">
+    <value>Set up PrivaPub</value>
+  </data>
+  <data name="You are signed in" xml:space="preserve">
+    <value>You are signed in</value>
+  </data>
+  <data name="This server is set up" xml:space="preserve">
+    <value>This server is set up</value>
+  </data>
+  <data name="It has an administrator already: sign in, or join with a group's invitation." xml:space="preserve">
+    <value>It has an administrator already: sign in, or join with a group's invitation.</value>
+  </data>
+  <data name="Join with an invitation" xml:space="preserve">
+    <value>Join with an invitation</value>
+  </data>
+  <data name="This server has no administrator yet. The first login made here becomes it, with its first persona; after that, joining takes a group's invitation." xml:space="preserve">
+    <value>This server has no administrator yet. The first login made here becomes it, with its first persona; after that, joining takes a group's invitation.</value>
+  </data>
+  <data name="Your login" xml:space="preserve">
+    <value>Your login</value>
+  </data>
+  <data name="Repeat the password" xml:space="preserve">
+    <value>Repeat the password</value>
+  </data>
+  <data name="Your first persona" xml:space="preserve">
+    <value>Your first persona</value>
+  </data>
+  <data name="Others see your personas, never your login." xml:space="preserve">
+    <value>Others see your personas, never your login.</value>
+  </data>
+  <data name="The two passwords don't match." xml:space="preserve">
+    <value>The two passwords don't match.</value>
+  </data>
+  <data name="PrivaPub is set up: you are its administrator." xml:space="preserve">
+    <value>PrivaPub is set up: you are its administrator.</value>
+  </data>
+  <data name="A persona of yours joins a group by its invitation in Groups." xml:space="preserve">
+    <value>A persona of yours joins a group by its invitation in Groups.</value>
+  </data>
+  <data name="A group's invitation makes your login here, and your first persona joins the group." xml:space="preserve">
+    <value>A group's invitation makes your login here, and your first persona joins the group.</value>
+  </data>
+  <data name="I have a login: sign in" xml:space="preserve">
+    <value>I have a login: sign in</value>
+  </data>
+  <data name="Welcome: your persona is in the group." xml:space="preserve">
+    <value>Welcome: your persona is in the group.</value>
+  </data>
+  <data name="This server has no administrator yet" xml:space="preserve">
+    <value>This server has no administrator yet</value>
+  </data>
+  <data name="Set it up: the first login made becomes its administrator." xml:space="preserve">
+    <value>Set it up: the first login made becomes its administrator.</value>
+  </data>
+  <data name="Have an invitation?" xml:space="preserve">
+    <value>Have an invitation?</value>
+  </data>
+  <data name="This login has no persona to act as yet: make one in Settings." xml:space="preserve">
+    <value>This login has no persona to act as yet: make one in Settings.</value>
+  </data>
+  <data name="Invitation link, for someone without a login here" xml:space="preserve">
+    <value>Invitation link, for someone without a login here</value>
+  </data>
 </root>