Add auto-start targets feature with dashboard section

- Add auto_start boolean field to PictureTarget model (persisted per-target)
- Wire auto_start through API schemas, routes, and store
- Auto-start targets on server boot in main.py lifespan
- Add star toggle button on target cards (next to delete button)
- Add auto-start section on dashboard between performance and profiles
- Remove auto-start section from profiles tab

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/wled_controller/static/js/features/kc-targets.js

@@ -70,7 +70,10 @@ export function createKCTargetCard(target, sourceMap, patternTemplateMap, valueS
 
     return `
         <div class="card" data-kc-target-id="${target.id}">
-            <button class="card-remove-btn" onclick="deleteKCTarget('${target.id}')" title="${t('common.delete')}">&#x2715;</button>
+            <div class="card-top-actions">
+                <button class="card-autostart-btn${target.auto_start ? ' active' : ''}" onclick="toggleTargetAutoStart('${target.id}', ${!target.auto_start})" title="${target.auto_start ? t('autostart.toggle.enabled') : t('autostart.toggle.disabled')}">&#x2605;</button>
+                <button class="card-remove-btn" onclick="deleteKCTarget('${target.id}')" title="${t('common.delete')}">&#x2715;</button>
+            </div>
             <div class="card-header">
                 <div class="card-title">
                     ${escapeHtml(target.name)}