feat(ui): priority dropdown badge, delete ticket modal, Empty state component; Convex mutations (updatePriority/remove); layout polish

- PrioritySelect with translucent badge + Select options
- DeleteTicketDialog with confirmation and icons
- Empty UI primitives and basic usage (kept simple to ensure build)
- Convex: tickets.updatePriority & tickets.remove
- Header: integrate priority select, delete action, avatar-rich assignee select

web/convex/tickets.ts

@@ -333,6 +333,21 @@ export const changeQueue = mutation({
   },
 });
 
+export const updatePriority = mutation({
+  args: { ticketId: v.id("tickets"), priority: v.string(), actorId: v.id("users") },
+  handler: async (ctx, { ticketId, priority, actorId }) => {
+    const now = Date.now();
+    await ctx.db.patch(ticketId, { priority, updatedAt: now });
+    const pt: Record<string, string> = { LOW: "Baixa", MEDIUM: "Média", HIGH: "Alta", URGENT: "Urgente" };
+    await ctx.db.insert("ticketEvents", {
+      ticketId,
+      type: "PRIORITY_CHANGED",
+      payload: { to: priority, toLabel: pt[priority] ?? priority, actorId },
+      createdAt: now,
+    });
+  },
+});
+
 export const playNext = mutation({
   args: {
     tenantId: v.string(),
@@ -422,3 +437,30 @@ export const playNext = mutation({
     }
   },
 });
+
+export const remove = mutation({
+  args: { ticketId: v.id("tickets"), actorId: v.id("users") },
+  handler: async (ctx, { ticketId, actorId }) => {
+    // delete comments (and attachments)
+    const comments = await ctx.db
+      .query("ticketComments")
+      .withIndex("by_ticket", (q) => q.eq("ticketId", ticketId))
+      .collect();
+    for (const c of comments) {
+      for (const att of c.attachments ?? []) {
+        try { await ctx.storage.delete(att.storageId); } catch {}
+      }
+      await ctx.db.delete(c._id);
+    }
+    // delete events
+    const events = await ctx.db
+      .query("ticketEvents")
+      .withIndex("by_ticket", (q) => q.eq("ticketId", ticketId))
+      .collect();
+    for (const ev of events) await ctx.db.delete(ev._id);
+    // delete ticket
+    await ctx.db.delete(ticketId);
+    // (optional) event is moot after deletion
+    return true;
+  },
+});