feat: follow-by-handle form on following and users pages

crates/adapters/template-askama/templates/following.html

@@ -4,6 +4,12 @@
 {% if let Some(err) = error %}
 <p class="error">{{ err }}</p>
 {% endif %}
+<form method="POST" action="/users/{{ user_id }}/follow" class="follow-form">
+  <input type="hidden" name="_csrf" value="{{ ctx.csrf_token }}">
+  <input type="hidden" name="redirect_after" value="/social/following">
+  <input type="text" name="handle" placeholder="@user@instance.tld" required>
+  <button type="submit">Follow</button>
+</form>
 {% if actors.is_empty() %}
 <p>Not following anyone yet. Follow remote users from your <a href="/users/{{ user_id }}">profile page</a>.</p>
 {% else %}

crates/adapters/template-askama/templates/users.html

@@ -2,6 +2,14 @@
 {% block content %}
 <div class="users-list">
   <h2 class="page-title">Members</h2>
+  {% if let Some(viewer_id) = ctx.user_id %}
+  <form method="POST" action="/users/{{ viewer_id }}/follow" class="follow-form">
+    <input type="hidden" name="_csrf" value="{{ ctx.csrf_token }}">
+    <input type="hidden" name="redirect_after" value="/users">
+    <input type="text" name="handle" placeholder="@user@instance.tld" required>
+    <button type="submit">Follow</button>
+  </form>
+  {% endif %}
   {% for user in users %}
   <div class="user-row">
     <div class="user-avatar">{{ user.initial }}</div>

crates/presentation/src/forms.rs

@@ -85,6 +85,8 @@ pub struct FollowForm {
     pub handle: String,
     #[serde(rename = "_csrf", default)]
     pub csrf_token: String,
+    #[serde(default)]
+    pub redirect_after: Option<String>,
 }
 
 #[derive(Deserialize)]

crates/presentation/src/handlers/html.rs

@@ -718,12 +718,20 @@ pub async fn follow_remote_user(
     if crate::csrf::mismatch(&csrf, &form.csrf_token) {
         return StatusCode::FORBIDDEN.into_response();
     }
+    let redirect_base = form
+        .redirect_after
+        .as_deref()
+        .filter(|u| u.starts_with('/') && !u.starts_with("//"))
+        .unwrap_or(&format!("/users/{}", profile_user_uuid))
+        .to_string();
+
     match state.ap_service.follow(user_id.value(), &form.handle).await {
-        Ok(()) => Redirect::to(&format!("/users/{}", profile_user_uuid)).into_response(),
+        Ok(()) => Redirect::to(&redirect_base).into_response(),
         Err(e) => {
             tracing::error!("follow error: {:?}", e);
             let msg = encode_error(&e.to_string());
-            Redirect::to(&format!("/users/{}?error={}", profile_user_uuid, msg)).into_response()
+            let sep = if redirect_base.contains('?') { '&' } else { '?' };
+            Redirect::to(&format!("{}{}error={}", redirect_base, sep, msg)).into_response()
         }
     }
 }