feat(astro): default slot on SignIn/SignUp/UserButton/AccountSecurity (6.1/6.3)

Each form component now renders a default-empty <slot/> so consumers can append extras (OAuth buttons, magic-link/forgot links, extra fields, account panels) while the zero-config render (no slot content) preserves the prior DOM/classes/props. Additive/minor (6.3 - no-slot behavior unchanged). SignedIn/SignedOut were already slot-based.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: MajorTal

astro/src/components/AccountSecurity.astro

@@ -160,6 +160,9 @@ const show = (s: Section): boolean =>
         <a class="r402-as-link" href="/auth/sign-in/oauth/google/start?intent=link">Connect Google</a>
       </section>
     )}
+    <!-- Consumer-supplied extra panels; empty by default (prior DOM
+         preserved). §6.1/§6.3. -->
+    <slot />
   </div>
 )}
 

astro/src/components/SignIn.astro

@@ -70,6 +70,10 @@ const { returnTo = "/", class: className = "" } = Astro.props;
   </label>
 
   <button type="submit" class="r402-submit">Sign in</button>
+  <!-- Slot for consumer-supplied extras (OAuth buttons, a magic-link link,
+       a "forgot password" link, extra fields). Empty by default, so the
+       zero-config render preserves the prior DOM (§6.1/§6.3). -->
+  <slot />
 </form>
 
 <style>

astro/src/components/SignUp.astro

@@ -49,6 +49,9 @@ const { returnTo = "/", class: className = "" } = Astro.props;
   </label>
 
   <button type="submit" class="r402-submit">Create account</button>
+  <!-- Consumer-supplied extras (terms checkbox, OAuth buttons, etc.); empty
+       by default, so the zero-config render preserves the prior DOM (§6.1/§6.3). -->
+  <slot />
 </form>
 
 <style>

astro/src/components/UserButton.astro

@@ -73,6 +73,9 @@ try {
     <input type="hidden" name="_csrf" value={csrfToken} />
     <span class="r402-user-label">{displayLabel}</span>
     <button type="submit" class="r402-sign-out">Sign out</button>
+    <!-- Consumer extras (menu items, account links); empty by default so the
+         zero-config render preserves the prior DOM (§6.1/§6.3). -->
+    <slot />
   </form>
 )}