chore: import upstream snapshot with attribution

model/README.md

@@ -0,0 +1,163 @@
+# Model Package
+
+The `model` package provides a structured data storage interface with CRUD operations, query filtering, and multiple database backends.
+
+Unlike the `store` package (which is a raw KV abstraction), `model` provides structured data access with schema awareness, WHERE queries, ordering, pagination, and indexes.
+
+## Quick Start
+
+```go
+import (
+    "context"
+    "go-micro.dev/v5/model"
+)
+
+// Define your model with struct tags
+type User struct {
+    ID    string `json:"id" model:"key"`
+    Name  string `json:"name" model:"index"`
+    Email string `json:"email"`
+    Age   int    `json:"age"`
+}
+
+// Create a model and register your type
+db := model.NewModel()
+db.Register(&User{})
+
+ctx := context.Background()
+
+// Create
+db.Create(ctx, &User{ID: "1", Name: "Alice", Email: "alice@example.com", Age: 30})
+
+// Read
+user := &User{}
+db.Read(ctx, "1", user)
+fmt.Println(user.Name) // "Alice"
+
+// Update
+user.Name = "Alice Smith"
+db.Update(ctx, user)
+
+// Delete
+db.Delete(ctx, "1", &User{})
+```
+
+## Struct Tags
+
+| Tag | Description | Example |
+|-----|-------------|---------|
+| `model:"key"` | Primary key field | `ID string \`model:"key"\`` |
+| `model:"index"` | Create an index on this field | `Name string \`model:"index"\`` |
+| `json:"name"` | Column name in the database | `Name string \`json:"name"\`` |
+
+If no `model:"key"` tag is found, the package defaults to a field with `json:"id"` or column name `id`.
+
+## Querying
+
+```go
+// Filter by field value
+var users []*User
+db.List(ctx, &users, model.Where("name", "Alice"))
+
+// Comparison operators
+db.List(ctx, &users, model.WhereOp("age", ">", 25))
+db.List(ctx, &users, model.WhereOp("name", "LIKE", "Ali%"))
+
+// Ordering
+db.List(ctx, &users, model.OrderAsc("name"))
+db.List(ctx, &users, model.OrderDesc("age"))
+
+// Pagination
+db.List(ctx, &users, model.Limit(10), model.Offset(20))
+
+// Combine
+db.List(ctx, &users,
+    model.Where("status", "active"),
+    model.WhereOp("age", ">=", 18),
+    model.OrderDesc("created_at"),
+    model.Limit(25),
+)
+
+// Count
+total, _ := db.Count(ctx, &User{})
+active, _ := db.Count(ctx, &User{}, model.Where("status", "active"))
+```
+
+## Backends
+
+### Memory (Development & Testing)
+
+```go
+import "go-micro.dev/v5/model"
+
+db := model.NewModel()
+```
+
+In-memory storage. No persistence. Fast. Good for tests and prototyping.
+
+### SQLite (Development & Single-Node Production)
+
+```go
+import "go-micro.dev/v5/model/sqlite"
+
+db := sqlite.New("app.db")       // File-based
+db := sqlite.New(":memory:")     // In-memory (testing)
+```
+
+Embedded SQL database. Zero external dependencies. Supports WHERE, indexes, ordering natively.
+
+### Postgres (Production)
+
+```go
+import "go-micro.dev/v5/model/postgres"
+
+db := postgres.New("postgres://user:pass@localhost/mydb?sslmode=disable")
+```
+
+Full PostgreSQL support. Best for production with rich query capabilities.
+
+## Table Names
+
+By default, the table name is the lowercase struct name + "s" (e.g., `User` → `users`). Override with `model.WithTable`:
+
+```go
+db.Register(&User{}, model.WithTable("app_users"))
+```
+
+## Model Interface
+
+All backends implement the `model.Model` interface:
+
+```go
+type Model interface {
+    Init(...Option) error
+    Register(v interface{}, opts ...RegisterOption) error
+    Create(ctx context.Context, v interface{}) error
+    Read(ctx context.Context, key string, v interface{}) error
+    Update(ctx context.Context, v interface{}) error
+    Delete(ctx context.Context, key string, v interface{}) error
+    List(ctx context.Context, result interface{}, opts ...QueryOption) error
+    Count(ctx context.Context, v interface{}, opts ...QueryOption) (int64, error)
+    Close() error
+    String() string
+}
+```
+
+## Model vs Store
+
+| Feature | `store` | `model` |
+|---------|---------|---------|
+| Data format | Raw `[]byte` | Go structs |
+| Queries | Key prefix/suffix only | WHERE, operators, LIKE |
+| Ordering | None | ORDER BY field ASC/DESC |
+| Pagination | Limit/Offset on keys | Limit/Offset on results |
+| Indexes | None | Via `model:"index"` tag |
+| Schema | None (schemaless KV) | Auto-created from struct |
+| Backends | Memory, File, MySQL, Postgres, NATS | Memory, SQLite, Postgres |
+| Use case | Config, sessions, cache | Application data, entities |
+
+## Testing
+
+```bash
+go test ./model/...
+```