feat: implement workspace management and member invitations

- Added tenant API for managing workspaces, including listing, creating, and inviting members.
- Introduced new models for organizations, workspaces, and workspace memberships in the backend.
- Created frontend components for workspace administration, allowing users to manage workspaces and invite members.
- Updated document listing to support workspace-specific filtering.
- Implemented account settings page for user profile management and password changes.
- Added end-to-end tests for workspace administration and dashboard functionalities.

backend/app/models/tenant.py

@@ -0,0 +1,64 @@
+from datetime import datetime
+
+from sqlalchemy import Boolean, DateTime, ForeignKey, String, UniqueConstraint, func
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.database import Base
+
+
+class Organization(Base):
+    __tablename__ = "organizations"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    name: Mapped[str] = mapped_column(String(160), nullable=False)
+    slug: Mapped[str] = mapped_column(String(180), unique=True, index=True, nullable=False)
+    owner_id: Mapped[int] = mapped_column(ForeignKey("users.id"), index=True, nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+
+
+class Workspace(Base):
+    __tablename__ = "workspaces"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    organization_id: Mapped[int] = mapped_column(ForeignKey("organizations.id"), index=True, nullable=False)
+    name: Mapped[str] = mapped_column(String(160), nullable=False)
+    slug: Mapped[str] = mapped_column(String(180), nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+    __table_args__ = (UniqueConstraint("organization_id", "slug", name="uq_workspace_org_slug"),)
+
+
+class WorkspaceMembership(Base):
+    __tablename__ = "workspace_memberships"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    workspace_id: Mapped[int] = mapped_column(ForeignKey("workspaces.id"), index=True, nullable=False)
+    user_id: Mapped[int] = mapped_column(ForeignKey("users.id"), index=True, nullable=False)
+    role: Mapped[str] = mapped_column(String(30), default="member", nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+    __table_args__ = (UniqueConstraint("workspace_id", "user_id", name="uq_workspace_member"),)
+
+
+class WorkspaceInvitation(Base):
+    __tablename__ = "workspace_invitations"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    workspace_id: Mapped[int] = mapped_column(ForeignKey("workspaces.id"), index=True, nullable=False)
+    inviter_id: Mapped[int] = mapped_column(ForeignKey("users.id"), nullable=False)
+    email: Mapped[str] = mapped_column(String(255), index=True, nullable=False)
+    role: Mapped[str] = mapped_column(String(30), default="member", nullable=False)
+    token: Mapped[str] = mapped_column(String(128), unique=True, index=True, nullable=False)
+    accepted: Mapped[bool] = mapped_column(Boolean, default=False, nullable=False)
+    expires_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+
+
+class TenantAuditEvent(Base):
+    __tablename__ = "tenant_audit_events"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    organization_id: Mapped[int] = mapped_column(ForeignKey("organizations.id"), index=True, nullable=False)
+    workspace_id: Mapped[int | None] = mapped_column(ForeignKey("workspaces.id"), index=True)
+    actor_id: Mapped[int] = mapped_column(ForeignKey("users.id"), nullable=False)
+    action: Mapped[str] = mapped_column(String(80), nullable=False)
+    target: Mapped[str] = mapped_column(String(255), nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now(), nullable=False)