feat(repository): implement user repository (#10967)

## Summary

This PR introduces the relational user repository for backend v3,
including schema, repository APIs, reducers/projections, and tests for
both human and machine users.

## What changed

* Added user-focused relational migrations (users, verifications,
metadata, PATs, machine keys, passkeys, identity provider links) and
related FK wiring.
* Implemented/expanded repository domain contracts and storage
implementations for human and machine user flows.
* Added support for machine secret handling and aligned access token
type modeling.
* Extended user domain models (verifications, password/email/phone/TOTP
state, passkeys, metadata, invite handling, identity provider links).
* Updated projection/reduction coverage and integration tests for key
user lifecycle events.
* Regenerated and updated mocks/enums plus supporting database
change/column utilities.

## Notes for reviewers

* This PR is large because it establishes the foundational relational
user storage layer and related test scaffolding. Sorry for that.

## Closes

Closes #10218
Closes #10224
Closes #10225
Closes #10209
Closes #10802

---------

Co-authored-by: Iraq Jaber <[email protected]>
Co-authored-by: Copilot <[email protected]>
Co-authored-by: Marco A. <[email protected]>
Co-authored-by: Tim Möhlmann <[email protected]>

backend/v3/storage/database/operators.go

@@ -31,7 +31,7 @@ func (b wrappedValue[V]) WriteArg(builder *StatementBuilder) {
 var _ argWriter = (*wrappedValue[string])(nil)
 
 type Value interface {
-	Boolean | Number | Text | Instruction | Bytes
+	Boolean | Number | Text | Instruction | Bytes | any
 }
 
 //go:generate enumer -type NumberOperation,TextOperation,BytesOperation -linecomment -output ./operators_enumer.go