Add pending account provisioning for demoing to not-yet-existing accounts

An admin can now queue up an email address in advance (POST/GET/DELETE
/system/pending-provisioning) with a source user and an optional admin
flag. The moment that email actually verifies a real account - not raw
registration, which proves nothing about ownership - it gets a deep copy
of the source user's per-user API keys and every company they own
(company profile, aliases, competitors, monitor config, sources, source
documents, monitoring runs, reports, snapshots, detected changes, and
enrichment - not just the company row), plus an email notification
destination for its own address linked to the copied companies.

The clone logic (_copy_row/_clone_company in provisioning_service.py) is
generic over every table it touches via column introspection, so it
doesn't need hand-maintained field lists per model.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

apps/api/app/schemas/provisioning.py

@@ -0,0 +1,20 @@
+from __future__ import annotations
+
+import uuid
+from datetime import datetime
+
+from pydantic import BaseModel, EmailStr
+
+
+class PendingProvisioningCreate(BaseModel):
+    email: EmailStr
+    source_user_id: uuid.UUID
+    make_admin: bool = False
+
+
+class PendingProvisioningResponse(BaseModel):
+    id: uuid.UUID
+    email: str
+    source_user_id: uuid.UUID
+    make_admin: bool
+    created_at: datetime