ci: Update Magefile to include shortcuts for build, test, lint, and release

- Added Lint target: runs golangci-lint for code quality checks
- Added Release target: builds and packages releases (requires goreleaser)

Also fixed errcheck linting issue:
- Check error return from o.vars.SetVariable in AssignVariable

All mage targets work: build, run, test, testRPN, rpn, install, lint, release, repl, uninstall

2 files changed, 14 insertions, 2 deletions

diff --git a/Magefile.go b/Magefile.go
index 05ec508..29d94f8 100644
--- a/Magefile.go
+++ b/Magefile.go
@@ -53,6 +53,19 @@ func Install() error {
 	return sh.RunV("go", "install", "./cmd/gt")
 }
 
+// Lint runs golangci-lint for code quality checks.
+func Lint() error {
+	fmt.Println("Running golangci-lint...")
+	return sh.RunV("golangci-lint", "run", "./...")
+}
+
+// Release builds and packages the release for all platforms.
+func Release() error {
+	fmt.Println("Creating release...")
+	fmt.Println("Note: Requires goreleaser to be installed and configured.")
+	return sh.RunV("goreleaser", "release", "--clean")
+}
+
 // Repl starts the REPL mode.
 func Repl() error {
 	return sh.RunV("go", "run", "./cmd/gt", "--repl")
diff --git a/internal/rpn/operations.go b/internal/rpn/operations.go
index 3bd0fc1..d9965ed 100644
--- a/internal/rpn/operations.go
+++ b/internal/rpn/operations.go
@@ -711,8 +711,7 @@ func (o *Operations) AssignVariable(stack *Stack, name string) error {
 	}
 
 	// Convert Value to float64 for variable storage
-	o.vars.SetVariable(name, toNumber(val))
-	return nil
+	return o.vars.SetVariable(name, toNumber(val))
 }
 
 // UseVariable pushes a variable's value onto the stack.