feat: «Mi día», the few tickets I pick for today

A home panel with the tickets picked for today (10 at most), crossed out
as they get done and counted («1 de 3 terminados»), my open tickets to
add with one click, and what was left unfinished on my last day to carry
over. «☀ Mi día» on a ticket adds it or takes it out. The day is the
person's own (YYYY-MM-DD from the browser); private, no history (Mongo
`my_days`).

API: myDay(day), addToMyDay, removeFromMyDay; GET /api/me/day,
PUT/DELETE /api/me/day/{issue}. MCP: my_day.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

libs/api/tracker/infrastructure/src/lib/mongo/read-model.schemas.ts

@@ -111,6 +111,7 @@ export const ReadModels = {
   AlertTrace: 'AlertTrace',
   TreeFollow: 'TreeFollow',
   IssueReminder: 'IssueReminder',
+  MyDay: 'MyDay',
   Sprint: 'SprintReadModel',
   GitIntegration: 'GitIntegration',
   OutgoingWebhook: 'OutgoingWebhook',
@@ -385,6 +386,15 @@ export const IssueReminderSchema = SchemaFactory.createForClass(
 IssueReminderSchema.index({ sentAt: 1, at: 1 });
 IssueReminderSchema.index({ userId: 1, issueId: 1 });
 
+@Schema({ ...LOOSE, collection: 'my_days' })
+class MyDayDocument {
+  @Prop({ type: String }) userId!: string;
+  @Prop({ type: String }) day!: string;
+  @Prop({ type: [String] }) issueIds!: string[];
+}
+export const MyDaySchema = SchemaFactory.createForClass(MyDayDocument);
+MyDaySchema.index({ userId: 1, day: -1 }, { unique: true });
+
 @Schema({ ...LOOSE, collection: 'git_integrations' })
 class GitIntegrationDocument {
   /** The project's id. */
@@ -492,6 +502,7 @@ export const READ_MODEL_SCHEMAS = [
   { name: ReadModels.AlertTrace, schema: AlertTraceSchema },
   { name: ReadModels.TreeFollow, schema: TreeFollowSchema },
   { name: ReadModels.IssueReminder, schema: IssueReminderSchema },
+  { name: ReadModels.MyDay, schema: MyDaySchema },
   { name: ReadModels.CalendarFeed, schema: CalendarFeedSchema },
   { name: ReadModels.DashboardShare, schema: DashboardShareSchema },
   { name: ReadModels.PushSubscription, schema: PushSubscriptionSchema },