feat: add email campaigns database migration schema

apps/api/internal/api/api.go

@@ -133,6 +133,9 @@ func Run() {
 	hackathon.RegisterRoutes(hackathonHandler, huma.NewGroup(api, "/hackathon"), mw)
 
 	emailService := email.NewEmailService(hackathonRepo, userRepo, taskQueueClient, sesClient, r2Client, logger, config)
+	emailHandler := email.NewHandler(emailService, logger)
+	email.RegisterRoutes(emailHandler, huma.NewGroup(api, "/email"), mw)
+
 	batService := bat.NewBatService(applicationRepo, hackathonRepo, userRepo, batRunsRepo, emailService, txm, taskQueueClient, nil, config, logger)
 	applicationService := application.NewService(applicationRepo, userRepo, hackathonRepo, txm, r2Client, &config.CoreBuckets, nil, emailService, batService, config, logger)
 	applicationHandler := application.NewHandler(applicationService, batService, config, logger)

apps/api/internal/database/migrations/20260407214110_email_campaigns.sql

@@ -0,0 +1,94 @@
+-- +goose Up
+-- +goose StatementBegin
+
+create type email_campaign_status as enum (
+    'draft',
+    'scheduled',
+    'sending',
+    'sent',
+    'failed'
+);
+
+create type email_campaign_format as enum (
+    'text',
+    'html'
+);
+
+create type email_recipient_type as enum (
+    'admins',
+    'staff',
+    'accepted_applicants',
+    'rejected_applicants',
+    'waitlisted_applicants',
+    'visitors',
+    'interest_subscribers'
+);
+
+create table email_campaigns (
+    id uuid default gen_random_uuid() not null primary key,
+    hackathon_id text not null references hackathons(id) on delete cascade,
+
+    title text not null,
+    description text,
+    subject text not null,
+    body text not null,
+    format email_campaign_format default 'text'::email_campaign_format not null,
+
+    recipient_types email_recipient_type[] not null,
+    status email_campaign_status default 'draft'::email_campaign_status not null,
+
+    scheduled_at timestamptz,
+    sent_at timestamptz,
+    last_error text,
+
+    created_by_user_id uuid references users(id) on delete set null,
+    updated_by_user_id uuid references users(id) on delete set null,
+    created_at timestamptz default now() not null,
+    updated_at timestamptz default now() not null,
+
+    constraint email_campaigns_recipient_types_nonempty
+        check (cardinality(recipient_types) > 0),
+
+    constraint email_campaigns_scheduled_at_required
+        check (
+            status != 'scheduled'::email_campaign_status
+            or scheduled_at is not null
+        ),
+
+    constraint email_campaigns_sent_at_required
+        check (
+            status != 'sent'::email_campaign_status
+            or sent_at is not null
+        )
+);
+
+create index idx_email_campaigns_hackathon_id
+    on email_campaigns (hackathon_id);
+
+create index idx_email_campaigns_status
+    on email_campaigns (status);
+
+create index idx_email_campaigns_created_at
+    on email_campaigns (created_at desc);
+
+create index idx_email_campaigns_scheduled_at
+    on email_campaigns (scheduled_at)
+    where status = 'scheduled'::email_campaign_status;
+
+create trigger set_updated_at_email_campaigns
+    before update on email_campaigns
+    for each row
+    execute procedure update_modified_column();
+
+-- +goose StatementEnd
+
+-- +goose Down
+-- +goose StatementBegin
+
+drop trigger if exists set_updated_at_email_campaigns on email_campaigns;
+drop table if exists email_campaigns;
+drop type if exists email_recipient_type;
+drop type if exists email_campaign_format;
+drop type if exists email_campaign_status;
+
+-- +goose StatementEnd