feat: Gmail OAuth flow, per-user SMTP, message dedup, account disable toggle

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>
Agent-Logs-Url: https://github.com/christianlouis/pop_puller_to_gmail/sessions/b77800ca-b452-4427-b0bf-63403e906916

backend/app/models/database_models.py

@@ -446,6 +446,38 @@ class AuditLog(Base):
     )
 
 
+class UserSmtpConfig(Base):
+    """Per-user SMTP relay configuration for email forwarding fallback."""
+
+    __tablename__ = "user_smtp_configs"
+
+    id = Column(Integer, primary_key=True, index=True)
+    user_id = Column(
+        Integer, ForeignKey("users.id", ondelete="CASCADE"), nullable=False, unique=True
+    )
+
+    host = Column(String(255), nullable=False, default="smtp.gmail.com")
+    port = Column(Integer, nullable=False, default=587)
+    username = Column(String(255), nullable=False, default="")
+    encrypted_password = Column(Text, nullable=False, default="")
+    use_tls = Column(Boolean, default=True)
+
+    created_at = Column(
+        DateTime(timezone=True),
+        default=lambda: datetime.now(timezone.utc),
+        nullable=False,
+    )
+    updated_at = Column(
+        DateTime(timezone=True),
+        default=lambda: datetime.now(timezone.utc),
+        onupdate=lambda: datetime.now(timezone.utc),
+        nullable=False,
+    )
+
+    # Relationships
+    user = relationship("User", backref="smtp_config")
+
+
 class DownloadedMessageId(Base):
     """
     Tracks unique message IDs that have already been downloaded and forwarded.

backend/app/models/schemas.py

@@ -339,3 +339,35 @@ class ProviderPreset(BaseModel):
 
 class ProviderListResponse(BaseModel):
     providers: List[ProviderPreset]
+
+
+# User SMTP Config Schemas
+class UserSmtpConfigBase(BaseModel):
+    host: str = "smtp.gmail.com"
+    port: int = Field(587, gt=0, lt=65536)
+    username: str = ""
+    use_tls: bool = True
+
+
+class UserSmtpConfigUpdate(UserSmtpConfigBase):
+    password: Optional[str] = None  # Only provided when changing the password
+
+
+class UserSmtpConfigResponse(UserSmtpConfigBase):
+    id: int
+    user_id: int
+    has_password: bool  # True if a password is stored (value is never returned)
+    created_at: datetime
+    updated_at: datetime
+
+    model_config = ConfigDict(from_attributes=True)
+
+
+# Gmail OAuth Schemas
+class GmailAuthorizeResponse(BaseModel):
+    authorization_url: str
+
+
+class GmailCallbackRequest(BaseModel):
+    code: str
+    redirect_uri: str