feat: add pi-web version reporting

docs/faq.html

@@ -121,7 +121,8 @@
               <h2>What does <code>pi-web doctor</code> check?</h2>
               <p>
                 It checks whether the service shell and native service environment can find Node 22+, npm, Pi, and the Pi
-                Web binaries. It also reports user service lingering when relevant for server-style installs.
+                Web binaries. It also prints installed and running PI WEB versions when available, and reports user service
+                lingering when relevant for server-style installs.
               </p>
               <p>
                 If something works in your terminal but fails in doctor, treat that as a login-shell PATH mismatch and

docs/index.html

@@ -257,6 +257,7 @@
             <pre id="home-install"><code><span class="prompt">$</span> npm install -g @jmfederico/pi-web
 <span class="prompt">$</span> pi-web install
 <span class="prompt">$</span> pi-web doctor
+<span class="prompt">$</span> pi-web version
 <span class="comment"># Open http://127.0.0.1:8504</span></code></pre>
           </div>
         </div>

docs/install.html

@@ -138,7 +138,8 @@
 /pi-web install
 /pi-web status
 /pi-web logs
-/pi-web doctor</code></pre>
+/pi-web doctor
+/pi-web version</code></pre>
               </div>
             </section>
 
@@ -195,6 +196,7 @@
 
             <section id="manage-services">
               <h2>Manage services</h2>
+              <p><code>pi-web version</code> compares the installed package version with the versions reported by the running Web/UI and session daemon services.</p>
               <div class="code-card">
                 <div class="copy-row">
                   <strong>Useful commands</strong>
@@ -204,6 +206,7 @@
 <span class="prompt">$</span> pi-web logs
 <span class="prompt">$</span> pi-web restart
 <span class="prompt">$</span> pi-web doctor
+<span class="prompt">$</span> pi-web version
 
 <span class="comment"># From a checkout, install the split development services:</span>
 <span class="prompt">$</span> pi-web install --dev</code></pre>