Fix token modal and session token issues

- Fix create token modal z-index so it's not covered by backdrop
- Rename session tokens from "login" to "Web Session" for clarity
- Delete old session tokens when logging in (prevents accumulation)
- Filter out session tokens from dashboard display (users only see
  their manually created API tokens)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

src/cmdforge/web/templates/dashboard/tokens.html

@@ -129,9 +129,9 @@
 
 <!-- Create Token Modal -->
 <div id="create-token-modal" class="hidden fixed inset-0 z-50 overflow-y-auto" aria-modal="true" role="dialog">
-    <div class="min-h-screen px-4 text-center">
+    <div class="min-h-screen px-4 text-center flex items-center justify-center">
         <div class="fixed inset-0 bg-black bg-opacity-50" onclick="closeCreateTokenModal()"></div>
-        <div class="inline-block w-full max-w-md my-8 text-left align-middle bg-white shadow-xl rounded-lg">
+        <div class="relative z-10 w-full max-w-md text-left bg-white shadow-xl rounded-lg">
             <form id="create-token-form" onsubmit="createToken(event)">
                 <input type="hidden" name="csrf_token" value="{{ csrf_token() }}">
 
@@ -172,9 +172,9 @@
 
 <!-- Token Created Modal (shows the token once) -->
 <div id="token-created-modal" class="hidden fixed inset-0 z-50 overflow-y-auto" aria-modal="true" role="dialog">
-    <div class="min-h-screen px-4 text-center">
+    <div class="min-h-screen px-4 text-center flex items-center justify-center">
         <div class="fixed inset-0 bg-black bg-opacity-50"></div>
-        <div class="inline-block w-full max-w-lg my-8 text-left align-middle bg-white shadow-xl rounded-lg">
+        <div class="relative z-10 w-full max-w-lg text-left bg-white shadow-xl rounded-lg">
             <div class="p-6">
                 <div class="flex items-center mb-4">
                     <div class="w-10 h-10 bg-green-100 rounded-full flex items-center justify-center">