fix: clarify password labels and change password UI in Sovran Hub

- sovran-hub.nix: rename credential labels for clarity
  - "Free Account — Password" → "Free Account / Hub Login — Password"
  - "Root Password" → "Administrator (root) Password"
  - "SSH Passphrase" → "SSH Passphrase — use via: ssh root@localhost"
- service-detail.js: update Change Password button text
  - "Change Password" → "Change Free Account Password"
- service-detail.js: update Change Password modal
  - Title: "Change Free Account & Hub Login Password"
  - Description: adds Hub login warning
  - Warning note: warns about desktop AND Hub login change
  - Success message: "Free account & Hub login password changed successfully."

Agent-Logs-Url: https://github.com/naturallaw777/staging_alpha/sessions/2ac6f3cf-cf94-47e9-86ac-1321cd5ff728

Co-authored-by: naturallaw777 <99053422+naturallaw777@users.noreply.github.com>

app/sovran_systemsos_web/static/js/service-detail.js

@@ -267,7 +267,7 @@ async function openServiceDetailModal(unit, name, icon) {
           '</div>' : "") +
         (unit === "root-password-setup.service" ?
           '<hr class="matrix-actions-divider"><div class="matrix-actions-row">' +
-            '<button class="matrix-action-btn" id="sys-change-pw-btn">🔑 Change Password</button>' +
+            '<button class="matrix-action-btn" id="sys-change-pw-btn">🔑 Change Free Account Password</button>' +
           '</div>' : "") +
         '</div>';
     } else if (!data.enabled && !data.feature) {
@@ -534,8 +534,8 @@ function openSystemChangePasswordModal(unit, name, icon) {
   if (!$credsBody) return;
   $credsBody.innerHTML =
     '<div class="sys-chpw-header">' +
-      '<div class="sys-chpw-title">🔑 Change \'free\' Account Password</div>' +
-      '<div class="sys-chpw-desc">This updates the system login password for the <strong>free</strong> user account on this device.</div>' +
+      '<div class="sys-chpw-title">🔑 Change Free Account &amp; Hub Login Password</div>' +
+      '<div class="sys-chpw-desc">This updates the password for the <strong>free</strong> user account. <strong>This is also your Sovran Hub login password</strong> — both will change.</div>' +
     '</div>' +
     '<div class="matrix-form-group"><label class="matrix-form-label" for="sys-chpw-new">New Password</label>' +
     '<div class="pw-input-wrap">' +
@@ -548,7 +548,7 @@ function openSystemChangePasswordModal(unit, name, icon) {
     '<input class="matrix-form-input" type="password" id="sys-chpw-confirm" placeholder="Confirm new password" autocomplete="new-password">' +
     '<button type="button" class="pw-toggle-btn" id="sys-chpw-confirm-toggle" aria-label="Toggle password visibility">👁</button>' +
     '</div></div>' +
-    '<div class="pw-credentials-note">⚠ After changing, your updated password will appear in the System Passwords credentials tile. Make sure to remember it.</div>' +
+    '<div class="pw-credentials-note">⚠ This will change both your desktop login and Hub login password. After changing, your updated password will appear in the System Passwords credentials tile. Make sure to remember it — you will need it to sign back into the Hub.</div>' +
     '<div class="matrix-form-actions">' +
     '<button class="matrix-form-back" id="sys-chpw-back-btn">← Back</button>' +
     '<button class="matrix-form-submit" id="sys-chpw-submit-btn">Change Password</button>' +
@@ -609,7 +609,7 @@ function openSystemChangePasswordModal(unit, name, icon) {
         body: JSON.stringify({ new_password: newPassword, confirm_password: confirmPassword })
       });
       resultEl.className = "matrix-form-result success";
-      resultEl.textContent = "✅ System password changed successfully.";
+      resultEl.textContent = "✅ Free account & Hub login password changed successfully.";
       submitBtn.textContent = "Change Password";
       submitBtn.disabled = false;
     } catch (err) {