Ship Print Forge shop site (colors, photos, 3D viewer) (#2)

## Summary

- Rebrand the Django client template as Print Forge (`client_site` → `print_forge`) with shop + shipping enabled.
- Product listings support multiple photos, color variants (shared price/description/STL, per-color stock and photos), and a photo-first / 3D-second gallery.
- Public pages use 3D printer / printed-toy photography instead of leftover t-shirt mockups; beta CI deploys on `master`.

Closes #1
Infra: [server-infra#27](ai_ml_operations/server-infra#27) (easy deploy beta).

## Test plan

- [ ] Product page shows photo first, 3D model second; color swatches swap photos and stock
- [ ] Portal can upload multiple photos and per-color qty/images; STL stays shared
- [ ] Public home/about/gallery have no t-shirt mockups
- [ ] `manage.py test` passes
- [ ] After server-infra#27: beta deploy to `print-forge-preview.aimloperations.com`

Reviewed-on: #2

site/events/models.py

@@ -0,0 +1,111 @@
+from decimal import Decimal
+
+from django.db import models
+from django.urls import reverse
+from django.utils import timezone
+from django.utils.text import slugify
+
+from core.models import TimeStampedModel, UUIDPrimaryKeyModel
+
+
+class Event(UUIDPrimaryKeyModel, TimeStampedModel):
+    title = models.CharField(max_length=200)
+    slug = models.SlugField(max_length=220, unique=True)
+    description = models.TextField(blank=True)
+    starts_at = models.DateTimeField()
+    venue = models.CharField(max_length=200, blank=True)
+    capacity = models.PositiveIntegerField(default=0)
+    price = models.DecimalField(max_digits=10, decimal_places=2, default=Decimal("0"))
+    currency = models.CharField(max_length=8, default="usd")
+    is_published = models.BooleanField(default=False)
+
+    class Meta:
+        ordering = ["starts_at"]
+
+    def __str__(self) -> str:
+        return self.title
+
+    def get_absolute_url(self) -> str:
+        return reverse("events:detail", kwargs={"slug": self.slug})
+
+    def save(self, *args, **kwargs):
+        if not self.slug:
+            base = slugify(self.title)[:200] or "event"
+            slug = base
+            n = 2
+            while Event.objects.filter(slug=slug).exclude(pk=self.pk).exists():
+                slug = f"{base}-{n}"
+                n += 1
+            self.slug = slug
+        super().save(*args, **kwargs)
+
+    def tickets_held(self, *, exclude_order_id=None) -> int:
+        qs = self.ticket_orders.filter(
+            status__in=[
+                TicketOrder.Status.DRAFT,
+                TicketOrder.Status.OPEN,
+                TicketOrder.Status.PAID,
+            ]
+        )
+        if exclude_order_id:
+            qs = qs.exclude(pk=exclude_order_id)
+        return qs.aggregate(total=models.Sum("quantity"))["total"] or 0
+
+    @property
+    def tickets_sold(self) -> int:
+        return self.tickets_held()
+
+    @property
+    def seats_remaining(self) -> int | None:
+        if not self.capacity:
+            return None
+        return max(self.capacity - self.tickets_sold, 0)
+
+    @property
+    def is_upcoming(self) -> bool:
+        return self.starts_at >= timezone.now()
+
+
+class TicketOrder(UUIDPrimaryKeyModel, TimeStampedModel):
+    class Status(models.TextChoices):
+        DRAFT = "draft", "Draft"
+        OPEN = "open", "Open"
+        PAID = "paid", "Paid"
+        CANCELLED = "cancelled", "Cancelled"
+
+    number = models.CharField(max_length=32, unique=True)
+    event = models.ForeignKey(
+        Event, on_delete=models.PROTECT, related_name="ticket_orders"
+    )
+    email = models.EmailField()
+    customer_name = models.CharField(max_length=200, blank=True)
+    quantity = models.PositiveIntegerField(default=1)
+    amount = models.DecimalField(max_digits=10, decimal_places=2)
+    currency = models.CharField(max_length=8, default="usd")
+    status = models.CharField(
+        max_length=16, choices=Status.choices, default=Status.DRAFT
+    )
+    stripe_checkout_session_id = models.CharField(max_length=255, blank=True)
+    hosted_checkout_url = models.URLField(blank=True)
+    paid_at = models.DateTimeField(null=True, blank=True)
+
+    class Meta:
+        ordering = ["-created_at"]
+
+    def __str__(self) -> str:
+        return f"{self.number} · {self.event}"
+
+
+class Ticket(UUIDPrimaryKeyModel, TimeStampedModel):
+    order = models.ForeignKey(
+        TicketOrder, on_delete=models.CASCADE, related_name="tickets"
+    )
+    event = models.ForeignKey(Event, on_delete=models.PROTECT, related_name="tickets")
+    code = models.CharField(max_length=16, unique=True)
+    attendee_name = models.CharField(max_length=200, blank=True)
+
+    class Meta:
+        ordering = ["created_at"]
+
+    def __str__(self) -> str:
+        return self.code