refactor(button): consolidate button styles into Button.astro

Extends Button.astro with a center prop, native <button> element support
(type, disabled, aria-describedby), harmonised padding (.65rem), and
transition. Removes global .button, .button-small, .button-light, and
.button-center rules from components.css, layout.css, and typography.css.
Converts all inline class="button" usages across Header, HomeHero,
HomeFinancialHelp, HomeServicesIntro, FormShell, TeamPage, CareersPage,
and FaqPage to the <Button> component. Updates three scoped style
selectors to :global() to reach the child component's elements.

www/src/components/pages/CareersPage.astro

@@ -1,4 +1,5 @@
 ---
+import Button from '../Button.astro';
 const indeedUrl = 'https://www.indeed.com/cmp/Arizona-Institute-For-Autism/jobs';
 
 const benefits = [
@@ -41,7 +42,7 @@ const careerCards = [
     <h2>Join the AIA Team</h2>
     <p>Apply to join the Arizona Institute for Autism (AIA) team today. We are on a mission to improve special education and strengthen communities throughout Arizona.</p>
     <p>Our talented and passionate employees are a critical piece to the high-quality Autism services we provide along with our commitment to behavioral health, school solutions, and community outreach.</p>
-    <a class="button button-center" href={indeedUrl} target="_blank" rel="noopener noreferrer">View Open Positions</a>
+    <Button href={indeedUrl} target="_blank" center>View Open Positions</Button>
   </section>
 
   <!-- Our Benefits -->
@@ -129,7 +130,7 @@ const careerCards = [
           <img src="/assets/images/logo-BACB.png" alt="BACB logo" loading="lazy" />
         </div>
       </div>
-      <a class="button button-center" href={indeedUrl} target="_blank" rel="noopener noreferrer">View Open Positions</a>
+      <Button href={indeedUrl} target="_blank" center>View Open Positions</Button>
     </div>
   </section>
 
@@ -175,7 +176,7 @@ const careerCards = [
           </div>
         ))}
       </div>
-      <a class="button button-center" href={indeedUrl} target="_blank" rel="noopener noreferrer">View Open Positions</a>
+      <Button href={indeedUrl} target="_blank" center>View Open Positions</Button>
     </div>
   </section>
 

www/src/components/pages/FaqPage.astro

@@ -1,4 +1,5 @@
 ---
+import Button from '../Button.astro';
 ---
 <article class="faq-page">
   <div class="faq-source container source-page">
@@ -48,7 +49,7 @@
     <div class="container-narrow">
       <h2>Need Support in Getting an Autism Diagnosis?</h2>
       <p>To meet diagnostic criteria for ASD, a child must have persistent deficits in each of three areas of social communication and interaction plus at least two of four types of restricted repetitive behaviors. Consult with a Client Advocate today to receive individual and family support!</p>
-      <a class="button button-center" href="/client-consultation">Request an Appointment</a>
+      <Button href="/client-consultation" center>Request an Appointment</Button>
     </div>
   </section>
 </article>
@@ -583,7 +584,7 @@
     margin-bottom: .75rem;
   }
 
-  .faq-cta-secondary .button {
+  .faq-cta-secondary :global(.content-button) {
     margin-top: 1.5rem;
   }
 

www/src/components/pages/TeamPage.astro

@@ -1,4 +1,5 @@
 ---
+import Button from '../Button.astro';
 const groups = [
   {
     title: 'Board Certified Behavioral Analysts & Psychologists',
@@ -68,7 +69,7 @@ const groups = [
       <h2>Employment Opportunities</h2>
       <p>Apply online to join the AIA team! At the Arizona Institute for Autism (AIA) we are on a mission to improve special education and strengthen communities throughout Arizona.</p>
       <p>Our talented and passionate employees are a critical piece to the high-quality ABA therapy we provide along with our commitment to behavioral health, school solutions, and community outreach. For questions regarding open positions, please contact us at <a href="mailto:hr@azinstitute4autism.com">hr@azinstitute4autism.com</a>.</p>
-      <a class="button" href="/careers">View Open Positions</a>
+      <Button href="/careers">View Open Positions</Button>
     </div>
   </section>
 </article>
@@ -87,7 +88,7 @@ const groups = [
   .team-member h3 { font-family: var(--font-body); font-size: .8rem; margin-bottom: 0; }
   .team-member p { font-size: .85rem; margin: 0; }
   .team-careers { padding-block: 5rem; }
-  .team-careers .button { margin-left: 50%; margin-top: 4rem; translate: -50%; }
+  .team-careers :global(.content-button) { margin-left: 50%; margin-top: 4rem; translate: -50%; }
   @media (max-width: 950px) {
     .team-member { flex-basis: min(100%, 227px); }
   }