docs: Add CLAUDE.md with codebase guidance

Create comprehensive documentation for future Claude Code instances working in this repository, including:
- Development commands for testing, building, and code quality
- Core architecture overview of the SQL query builder system
- Directory structure and component explanations
- Testing patterns and conventions
- Key dependencies and their purposes

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

update_dataset.go

@@ -1,10 +1,10 @@
 package db
 
 import (
-	"git.fsdpf.net/go/db/v2/exec"
-	"git.fsdpf.net/go/db/v2/exp"
-	"git.fsdpf.net/go/db/v2/internal/errors"
-	"git.fsdpf.net/go/db/v2/internal/sb"
+	"git.fsdpf.net/go/db/exec"
+	"git.fsdpf.net/go/db/exp"
+	"git.fsdpf.net/go/db/internal/errors"
+	"git.fsdpf.net/go/db/internal/sb"
 )
 
 type UpdateDataset struct {
@@ -13,6 +13,7 @@ type UpdateDataset struct {
 	isPrepared   prepared
 	queryFactory exec.QueryFactory
 	err          error
+	hooks        exec.Hooks
 }
 
 var ErrUnsupportedUpdateTableType = errors.New("unsupported table type, a string or identifier expression is required")
@@ -84,6 +85,7 @@ func (ud *UpdateDataset) copy(clauses exp.UpdateClauses) *UpdateDataset {
 		isPrepared:   ud.isPrepared,
 		queryFactory: ud.queryFactory,
 		err:          ud.err,
+		hooks:        ud.hooks,
 	}
 }
 
@@ -232,8 +234,24 @@ func (ud *UpdateDataset) ReturnsColumns() bool {
 // Generates the UPDATE sql, and returns an exec.QueryExecutor with the sql set to the UPDATE statement
 //
 //	db.Update("test").Set(Record{"name":"Bob", update: time.Now()}).Executor()
-func (ud *UpdateDataset) Executor() exec.QueryExecutor {
-	return ud.queryFactory.FromSQLBuilder(ud.updateSQLBuilder())
+func (ud *UpdateDataset) Executor() (executor exec.QueryExecutor) {
+	if ud.hooks != nil {
+		ud.SetError(ud.hooks.Before(ud))
+	}
+	executor = ud.queryFactory.FromSQLBuilder(ud.updateSQLBuilder())
+	if ud.hooks != nil {
+		executor.Hook(func(result interface{}) error {
+			return ud.hooks.After(ud, result)
+		})
+	}
+	return executor
+}
+
+func (ud *UpdateDataset) WithHook(hooks exec.Hooks) *UpdateDataset {
+	if ud.hooks == nil {
+		ud.hooks = hooks
+	}
+	return ud
 }
 
 func (ud *UpdateDataset) updateSQLBuilder() sb.SQLBuilder {