fix(web-clipper): bouton rond transparent draggable + toggle affichage + refresh auto sidebar + fix bloc bookmark (v6.2.1)

- bouton flottant rond (44px), semi-transparent blur, hover plus fonce, deplacable souris (pos persistee storage)
- option afficher/cacher dans popup extension (showButton)
- clipper: notification instantanee des onglets FlowDeck via tabs.sendMessage + polling 15s + BroadcastChannel + visibilitychange
- fix bookmark template literal '+title+' -> \/\/\/\/\ (_page_editor_scripts.html)
- sync static/extension + zip

static/extension/popup.html

@@ -43,6 +43,8 @@ a{color:#2383E2;text-decoration:none}
   <button class="btn btn-secondary" id="save" style="flex:1;padding:7px;font-size:12px;">Save</button>
   <button class="btn btn-secondary" id="verify" style="flex:1;padding:7px;font-size:12px;">Verify</button>
 </div>
+<label style="display:flex;align-items:center;gap:8px;margin-top:12px;cursor:pointer;text-transform:none;letter-spacing:0;font-size:13px;color:#e0e0e0"><input type="checkbox" id="showButton" style="width:auto;accent-color:#2383E2"> Afficher le bouton flottant sur les pages</label>
+<p class="small" style="margin-left:22px">Rond, semi-transparent, déplaçable à la souris.</p>
 <div id="status" class="status"></div>
 <p class="small">Need a token? Open <a href="#" id="openFlowDeck">FlowDeck → Settings → API tokens</a> or <a href="#" id="openExtensions">Extensions</a>.</p>