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/column.go

@@ -2,6 +2,18 @@ package database
 
 import "go.uber.org/mock/gomock"
 
+// Column represents a column in a database table.
+type Column interface {
+	gomock.Matcher
+	argWriter
+	// WriteQualified writes the column with the table name as prefix.
+	WriteQualified(builder *StatementBuilder)
+	// WriteUnqualified writes the column without the table name as prefix.
+	WriteUnqualified(builder *StatementBuilder)
+	// Equals checks if two columns are equal.
+	Equals(col Column) bool
+}
+
 type Columns []Column
 
 // Matches implements [Column].
@@ -59,24 +71,22 @@ func (c Columns) Equals(col Column) bool {
 	return true
 }
 
-var _ Column = (Columns)(nil)
-
-// Column represents a column in a database table.
-type Column interface {
-	gomock.Matcher
-	// WriteQualified writes the column with the table name as prefix.
-	WriteQualified(builder *StatementBuilder)
-	// WriteUnqualified writes the column without the table name as prefix.
-	WriteUnqualified(builder *StatementBuilder)
-	// Equals checks if two columns are equal.
-	Equals(col Column) bool
+// WriteArg implements [Column].
+func (c Columns) WriteArg(builder *StatementBuilder) {
+	c.WriteQualified(builder)
 }
 
+var _ Column = (Columns)(nil)
+
 type column struct {
 	table string
 	name  string
 }
 
+func NewColumn(table, name string) Column {
+	return &column{table: table, name: name}
+}
+
 // Matches implements [Column].
 func (c column) Matches(x any) bool {
 	toMatch, ok := x.(*column)
@@ -91,10 +101,6 @@ func (c column) String() string {
 	return "database.column"
 }
 
-func NewColumn(table, name string) Column {
-	return &column{table: table, name: name}
-}
-
 // WriteQualified implements [Column].
 func (c column) WriteQualified(builder *StatementBuilder) {
 	builder.Grow(len(c.table) + len(c.name) + 1)
@@ -120,6 +126,26 @@ func (c *column) Equals(col Column) bool {
 	return c.table == toMatch.table && c.name == toMatch.name
 }
 
+// WriteArg implements [Column].
+func (c column) WriteArg(builder *StatementBuilder) {
+	c.WriteQualified(builder)
+}
+
+var _ Column = (*column)(nil)
+
+type functionColumn struct {
+	fn  function
+	col Column
+}
+
+type function string
+
+const (
+	_              function = ""
+	functionLower  function = "LOWER"
+	functionSHA256 function = "SHA256"
+)
+
 // LowerColumn returns a column that represents LOWER(col).
 func LowerColumn(col Column) Column {
 	return &functionColumn{fn: functionLower, col: col}
@@ -130,11 +156,6 @@ func SHA256Column(col Column) Column {
 	return &functionColumn{fn: functionSHA256, col: col}
 }
 
-type functionColumn struct {
-	fn  function
-	col Column
-}
-
 // Matches implements [Column].
 func (c *functionColumn) Matches(x any) bool {
 	toMatch, ok := x.(*functionColumn)
@@ -155,14 +176,6 @@ func (c *functionColumn) String() string {
 	return "database.functionColumn"
 }
 
-type function string
-
-const (
-	_              function = ""
-	functionLower  function = "LOWER"
-	functionSHA256 function = "SHA256"
-)
-
 // WriteQualified implements [Column].
 func (c functionColumn) WriteQualified(builder *StatementBuilder) {
 	builder.Grow(len(c.fn) + 2)
@@ -193,4 +206,9 @@ func (c *functionColumn) Equals(col Column) bool {
 	return c.col.Equals(toMatch.col)
 }
 
+// WriteArg implements [Column].
+func (c functionColumn) WriteArg(builder *StatementBuilder) {
+	c.WriteQualified(builder)
+}
+
 var _ Column = (*functionColumn)(nil)