fix: accessibility improvements and test infrastructure hardening

Add aria-labels to form controls (selects, checkboxes, switches), set
html lang attribute and page title, fix color contrast for --candle-dim
and --text-faint tokens, underline inline links, remove opacity hack.
Harden dev login endpoints with atomic findOneAndUpdate and tokenVersion
in JWT. Update Playwright timeouts and E2E test helpers.

app/pages/admin/events/create.vue

@@ -102,6 +102,7 @@
               </label>
               <USelect
                 v-model="eventForm.eventType"
+                aria-label="Event type"
                 :items="[
                   { label: 'Community Meetup', value: 'community' },
                   { label: 'Workshop', value: 'workshop' },
@@ -386,6 +387,7 @@
               <div class="series-select-row">
                 <USelect
                   v-model="selectedSeriesId"
+                  aria-label="Select series"
                   @update:model-value="onSeriesSelect"
                   :items="
                     availableSeries.map((series) => ({

app/pages/admin/members.vue

@@ -30,7 +30,7 @@
         />
       </div>
       <div class="field" style="margin-bottom: 0;">
-        <select v-model="circleFilter">
+        <select v-model="circleFilter" aria-label="Filter by circle">
           <option value="">All Circles</option>
           <option value="community">Community</option>
           <option value="founder">Founder</option>
@@ -55,6 +55,7 @@
           <tr>
             <th class="col-check">
               <UCheckbox
+                aria-label="Select all members"
                 :model-value="allVisibleSelected ? true : (someVisibleSelected ? 'indeterminate' : false)"
                 @update:model-value="toggleSelectAll"
               />
@@ -73,6 +74,7 @@
           <tr v-for="member in filteredMembers" :key="member._id">
             <td class="col-check">
               <UCheckbox
+                :aria-label="`Select ${member.name}`"
                 :model-value="selectedMemberIds.includes(member._id)"
                 @update:model-value="toggleSelect(member._id)"
               />