feat: no login experience and prem tokens

surfsense_backend/app/schemas/stripe.py

@@ -54,3 +54,48 @@ class StripeWebhookResponse(BaseModel):
     """Generic acknowledgement for Stripe webhook delivery."""
 
     received: bool = True
+
+
+class CreateTokenCheckoutSessionRequest(BaseModel):
+    """Request body for creating a premium token purchase checkout session."""
+
+    quantity: int = Field(ge=1, le=100)
+    search_space_id: int = Field(ge=1)
+
+
+class CreateTokenCheckoutSessionResponse(BaseModel):
+    """Response containing the Stripe-hosted checkout URL."""
+
+    checkout_url: str
+
+
+class TokenPurchaseRead(BaseModel):
+    """Serialized premium token purchase record."""
+
+    id: uuid.UUID
+    stripe_checkout_session_id: str
+    stripe_payment_intent_id: str | None = None
+    quantity: int
+    tokens_granted: int
+    amount_total: int | None = None
+    currency: str | None = None
+    status: str
+    completed_at: datetime | None = None
+    created_at: datetime
+
+    model_config = ConfigDict(from_attributes=True)
+
+
+class TokenPurchaseHistoryResponse(BaseModel):
+    """Response containing the user's premium token purchases."""
+
+    purchases: list[TokenPurchaseRead]
+
+
+class TokenStripeStatusResponse(BaseModel):
+    """Response describing token-buying availability and current quota."""
+
+    token_buying_enabled: bool
+    premium_tokens_used: int = 0
+    premium_tokens_limit: int = 0
+    premium_tokens_remaining: int = 0