feat: eliminate fmt, string concat — add core.Println, use Concat/Path everywhere

New primitive: core.Println() wraps fmt.Println.

Replaced across all test + example files:
- fmt.Println → Println (17 example files)
- fmt.Sprintf → Concat + Sprint
- dir + "/file" → Path(dir, "file") (path security)
- "str" + var → Concat("str", var) (AX consistency)

"fmt" import is now zero across all test files.
String concat with + is zero across all test files.

Remaining 9 stdlib imports (all Go infrastructure):
testing, context, time, sync, embed, io/fs, bytes, gzip, base64

558 tests, 84.5% coverage.

Co-Authored-By: Virgil <virgil@lethean.io>

action_example_test.go

@@ -2,7 +2,6 @@ package core_test
 
 import (
 	"context"
-	"fmt"
 
 	. "dappco.re/go/core"
 )
@@ -16,16 +15,16 @@ func ExampleAction_Run() {
 	r := c.Action("double").Run(context.Background(), NewOptions(
 		Option{Key: "n", Value: 21},
 	))
-	fmt.Println(r.Value)
+	Println(r.Value)
 	// Output: 42
 }
 
 func ExampleAction_Exists() {
 	c := New()
-	fmt.Println(c.Action("missing").Exists())
+	Println(c.Action("missing").Exists())
 
 	c.Action("present", func(_ context.Context, _ Options) Result { return Result{OK: true} })
-	fmt.Println(c.Action("present").Exists())
+	Println(c.Action("present").Exists())
 	// Output:
 	// false
 	// true
@@ -38,7 +37,7 @@ func ExampleAction_Run_panicRecovery() {
 	})
 
 	r := c.Action("boom").Run(context.Background(), NewOptions())
-	fmt.Println(r.OK)
+	Println(r.OK)
 	// Output: false
 }
 
@@ -55,6 +54,6 @@ func ExampleAction_Run_entitlementDenied() {
 	})
 
 	r := c.Action("premium").Run(context.Background(), NewOptions())
-	fmt.Println(r.OK)
+	Println(r.OK)
 	// Output: false
 }

action_test.go

@@ -24,7 +24,7 @@ func TestAction_NamedAction_Good_Invoke(t *testing.T) {
 	c := New()
 	c.Action("git.log", func(_ context.Context, opts Options) Result {
 		dir := opts.String("dir")
-		return Result{Value: "log from " + dir, OK: true}
+		return Result{Value: Concat("log from ", dir), OK: true}
 	})
 
 	r := c.Action("git.log").Run(context.Background(), NewOptions(

api_example_test.go

@@ -2,7 +2,6 @@ package core_test
 
 import (
 	"context"
-	"fmt"
 
 	. "dappco.re/go/core"
 )
@@ -12,14 +11,14 @@ func ExampleAPI_RegisterProtocol() {
 	c.API().RegisterProtocol("http", func(h *DriveHandle) (Stream, error) {
 		return &mockStream{response: []byte("pong")}, nil
 	})
-	fmt.Println(c.API().Protocols())
+	Println(c.API().Protocols())
 	// Output: [http]
 }
 
 func ExampleAPI_Stream() {
 	c := New()
 	c.API().RegisterProtocol("http", func(h *DriveHandle) (Stream, error) {
-		return &mockStream{response: []byte("connected to " + h.Name)}, nil
+		return &mockStream{response: []byte(Concat("connected to ", h.Name))}, nil
 	})
 	c.Drive().New(NewOptions(
 		Option{Key: "name", Value: "charon"},
@@ -30,7 +29,7 @@ func ExampleAPI_Stream() {
 	if r.OK {
 		stream := r.Value.(Stream)
 		resp, _ := stream.Receive()
-		fmt.Println(string(resp))
+		Println(string(resp))
 		stream.Close()
 	}
 	// Output: connected to charon
@@ -45,6 +44,6 @@ func ExampleCore_RemoteAction() {
 
 	// No colon — resolves locally
 	r := c.RemoteAction("status", context.Background(), NewOptions())
-	fmt.Println(r.Value)
+	Println(r.Value)
 	// Output: running
 }

array_example_test.go

@@ -1,7 +1,6 @@
 package core_test
 
 import (
-	"fmt"
 
 	. "dappco.re/go/core"
 )
@@ -12,8 +11,8 @@ func ExampleNewArray() {
 	a.Add("bravo")
 	a.Add("charlie")
 
-	fmt.Println(a.Len())
+	Println(a.Len())
-	fmt.Println(a.Contains("bravo"))
+	Println(a.Contains("bravo"))
 	// Output:
 	// 3
 	// true
@@ -25,7 +24,7 @@ func ExampleArray_AddUnique() {
 	a.AddUnique("alpha") // no duplicate
 	a.AddUnique("bravo")
 
-	fmt.Println(a.Len())
+	Println(a.Len())
 	// Output: 2
 }
 
@@ -37,6 +36,6 @@ func ExampleArray_Filter() {
 	a.Add(4)
 
 	r := a.Filter(func(n int) bool { return n%2 == 0 })
-	fmt.Println(r.OK)
+	Println(r.OK)
 	// Output: true
 }

command_example_test.go

@@ -1,7 +1,6 @@
 package core_test
 
 import (
-	"fmt"
 
 	. "dappco.re/go/core"
 )
@@ -15,7 +14,7 @@ func ExampleCore_Command_register() {
 		},
 	})
 
-	fmt.Println(c.Command("deploy/to/homelab").OK)
+	Println(c.Command("deploy/to/homelab").OK)
 	// Output: true
 }
 
@@ -27,7 +26,7 @@ func ExampleCore_Command_managed() {
 	})
 
 	cmd := c.Command("serve").Value.(*Command)
-	fmt.Println(cmd.IsManaged())
+	Println(cmd.IsManaged())
 	// Output: true
 }
 
@@ -36,6 +35,6 @@ func ExampleCore_Commands() {
 	c.Command("deploy", Command{Action: func(_ Options) Result { return Result{OK: true} }})
 	c.Command("test", Command{Action: func(_ Options) Result { return Result{OK: true} }})
 
-	fmt.Println(c.Commands())
+	Println(c.Commands())
 	// Output: [deploy test]
 }

config_example_test.go

@@ -1,7 +1,6 @@
 package core_test
 
 import (
-	"fmt"
 
 	. "dappco.re/go/core"
 )
@@ -11,8 +10,8 @@ func ExampleConfig_Set() {
 	c.Config().Set("database.host", "localhost")
 	c.Config().Set("database.port", 5432)
 
-	fmt.Println(c.Config().String("database.host"))
+	Println(c.Config().String("database.host"))
-	fmt.Println(c.Config().Int("database.port"))
+	Println(c.Config().Int("database.port"))
 	// Output:
 	// localhost
 	// 5432
@@ -23,8 +22,8 @@ func ExampleConfig_Enable() {
 	c.Config().Enable("dark-mode")
 	c.Config().Enable("beta-features")
 
-	fmt.Println(c.Config().Enabled("dark-mode"))
+	Println(c.Config().Enabled("dark-mode"))
-	fmt.Println(c.Config().EnabledFeatures())
+	Println(c.Config().EnabledFeatures())
 	// Output:
 	// true
 	// [dark-mode beta-features]
@@ -32,10 +31,10 @@ func ExampleConfig_Enable() {
 
 func ExampleConfigVar() {
 	v := NewConfigVar(42)
-	fmt.Println(v.Get(), v.IsSet())
+	Println(v.Get(), v.IsSet())
 
 	v.Unset()
-	fmt.Println(v.Get(), v.IsSet())
+	Println(v.Get(), v.IsSet())
 	// Output:
 	// 42 true
 	// 0 false

drive_example_test.go

@@ -1,7 +1,6 @@
 package core_test
 
 import (
-	"fmt"
 
 	. "dappco.re/go/core"
 )
@@ -13,8 +12,8 @@ func ExampleDrive_New() {
 		Option{Key: "transport", Value: "https://forge.lthn.ai"},
 	))
 
-	fmt.Println(c.Drive().Has("forge"))
+	Println(c.Drive().Has("forge"))
-	fmt.Println(c.Drive().Names())
+	Println(c.Drive().Names())
 	// Output:
 	// true
 	// [forge]
@@ -30,7 +29,7 @@ func ExampleDrive_Get() {
 	r := c.Drive().Get("charon")
 	if r.OK {
 		h := r.Value.(*DriveHandle)
-		fmt.Println(h.Transport)
+		Println(h.Transport)
 	}
 	// Output: http://10.69.69.165:9101
 }

embed_test.go

@@ -92,7 +92,7 @@ func TestEmbed_Extract_Good(t *testing.T) {
 	r := Extract(testFS, dir, nil)
 	assert.True(t, r.OK)
 
-	cr := (&Fs{}).New("/").Read(dir + "/testdata/test.txt")
+	cr := (&Fs{}).New("/").Read(Path(dir, "testdata/test.txt"))
 	assert.True(t, cr.OK)
 	assert.Equal(t, "hello from testdata\n", cr.Value)
 }
@@ -147,12 +147,12 @@ func TestEmbed_GeneratePack_Empty_Good(t *testing.T) {
 
 func TestEmbed_GeneratePack_WithFiles_Good(t *testing.T) {
 	dir := t.TempDir()
-	assetDir := dir + "/mygroup"
+	assetDir := Path(dir, "mygroup")
 	(&Fs{}).New("/").EnsureDir(assetDir)
-	(&Fs{}).New("/").Write(assetDir+"/hello.txt", "hello world")
+	(&Fs{}).New("/").Write(Path(assetDir, "hello.txt"), "hello world")
 
 	source := "package test\nimport \"dappco.re/go/core\"\nfunc example() {\n\t_, _ = core.GetAsset(\"mygroup\", \"hello.txt\")\n}\n"
-	goFile := dir + "/test.go"
+	goFile := Path(dir, "test.go")
 	(&Fs{}).New("/").Write(goFile, source)
 
 	sr := ScanAssets([]string{goFile})
@@ -174,10 +174,10 @@ func TestEmbed_Extract_WithTemplate_Good(t *testing.T) {
 
 	// Use a real temp dir with files
 	srcDir := t.TempDir()
-	(&Fs{}).New("/").Write(srcDir+"/plain.txt", "static content")
+	(&Fs{}).New("/").Write(Path(srcDir, "plain.txt"), "static content")
-	(&Fs{}).New("/").Write(srcDir+"/greeting.tmpl", "Hello {{.Name}}!")
+	(&Fs{}).New("/").Write(Path(srcDir, "greeting.tmpl"), "Hello {{.Name}}!")
-	(&Fs{}).New("/").EnsureDir(srcDir+"/sub")
+	(&Fs{}).New("/").EnsureDir(Path(srcDir, "sub"))
-	(&Fs{}).New("/").Write(srcDir+"/sub/nested.txt", "nested")
+	(&Fs{}).New("/").Write(Path(srcDir, "sub/nested.txt"), "nested")
 
 	_ = tmplDir
 	fsys := DirFS(srcDir)
@@ -189,24 +189,24 @@ func TestEmbed_Extract_WithTemplate_Good(t *testing.T) {
 	f := (&Fs{}).New("/")
 
 	// Plain file copied
-	cr := f.Read(dir + "/plain.txt")
+	cr := f.Read(Path(dir, "plain.txt"))
 	assert.True(t, cr.OK)
 	assert.Equal(t, "static content", cr.Value)
 
 	// Template processed and .tmpl stripped
-	gr := f.Read(dir + "/greeting")
+	gr := f.Read(Path(dir, "greeting"))
 	assert.True(t, gr.OK)
 	assert.Equal(t, "Hello World!", gr.Value)
 
 	// Nested directory preserved
-	nr := f.Read(dir + "/sub/nested.txt")
+	nr := f.Read(Path(dir, "sub/nested.txt"))
 	assert.True(t, nr.OK)
 	assert.Equal(t, "nested", nr.Value)
 }
 
 func TestEmbed_Extract_BadTargetDir_Ugly(t *testing.T) {
 	srcDir := t.TempDir()
-	(&Fs{}).New("/").Write(srcDir+"/f.txt", "x")
+	(&Fs{}).New("/").Write(Path(srcDir, "f.txt"), "x")
 	r := Extract(DirFS(srcDir), "/nonexistent/deeply/nested/impossible", nil)
 	// Should fail gracefully, not panic
 	_ = r
@@ -248,7 +248,7 @@ func TestEmbed_EmbedFS_Original_Good(t *testing.T) {
 func TestEmbed_Extract_NilData_Good(t *testing.T) {
 	dir := t.TempDir()
 	srcDir := t.TempDir()
-	(&Fs{}).New("/").Write(srcDir+"/file.txt", "no template")
+	(&Fs{}).New("/").Write(Path(srcDir, "file.txt"), "no template")
 
 	r := Extract(DirFS(srcDir), dir, nil)
 	assert.True(t, r.OK)

entitlement_example_test.go

@@ -2,14 +2,13 @@ package core_test
 
 import (
 	"context"
-	"fmt"
 
 	. "dappco.re/go/core"
 )
 
 func ExampleEntitlement_UsagePercent() {
 	e := Entitlement{Limit: 100, Used: 75}
-	fmt.Println(e.UsagePercent())
+	Println(e.UsagePercent())
 	// Output: 75
 }
 
@@ -31,9 +30,9 @@ func ExampleCore_SetEntitlementChecker() {
 		return Entitlement{Allowed: true, Limit: limit, Used: used, Remaining: remaining}
 	})
 
-	fmt.Println(c.Entitled("social.accounts", 2).Allowed)
+	Println(c.Entitled("social.accounts", 2).Allowed)
-	fmt.Println(c.Entitled("social.accounts", 5).Allowed)
+	Println(c.Entitled("social.accounts", 5).Allowed)
-	fmt.Println(c.Entitled("ai.credits").NearLimit(0.9))
+	Println(c.Entitled("ai.credits").NearLimit(0.9))
 	// Output:
 	// true
 	// false
@@ -44,10 +43,10 @@ func ExampleCore_RecordUsage() {
 	c := New()
 	var recorded string
 	c.SetUsageRecorder(func(action string, qty int, _ context.Context) {
-		recorded = fmt.Sprintf("%s:%d", action, qty)
+		recorded = Concat(action, ":", Sprint(qty))
 	})
 
 	c.RecordUsage("ai.credits", 10)
-	fmt.Println(recorded)
+	Println(recorded)
 	// Output: ai.credits:10
 }

error_example_test.go

@@ -1,15 +1,14 @@
 package core_test
 
 import (
-	"fmt"
 
 	. "dappco.re/go/core"
 )
 
 func ExampleE() {
 	err := E("cache.Get", "key not found", nil)
-	fmt.Println(Operation(err))
+	Println(Operation(err))
-	fmt.Println(ErrorMessage(err))
+	Println(ErrorMessage(err))
 	// Output:
 	// cache.Get
 	// key not found
@@ -18,8 +17,8 @@ func ExampleE() {
 func ExampleWrap() {
 	cause := NewError("connection refused")
 	err := Wrap(cause, "database.Connect", "failed to reach host")
-	fmt.Println(Operation(err))
+	Println(Operation(err))
-	fmt.Println(Is(err, cause))
+	Println(Is(err, cause))
 	// Output:
 	// database.Connect
 	// true
@@ -29,6 +28,6 @@ func ExampleRoot() {
 	cause := NewError("original")
 	wrapped := Wrap(cause, "op1", "first wrap")
 	double := Wrap(wrapped, "op2", "second wrap")
-	fmt.Println(Root(double))
+	Println(Root(double))
 	// Output: original
 }

error_test.go

@@ -198,7 +198,7 @@ func TestError_ErrorJoin_Good(t *testing.T) {
 
 func TestError_ErrorPanic_Reports_Good(t *testing.T) {
 	dir := t.TempDir()
-	path := dir + "/crashes.json"
+	path := Path(dir, "crashes.json")
 
 	// Create ErrorPanic with file output
 	c := New()
@@ -213,7 +213,7 @@ func TestError_ErrorPanic_Reports_Good(t *testing.T) {
 
 func TestError_ErrorPanic_CrashFile_Good(t *testing.T) {
 	dir := t.TempDir()
-	path := dir + "/crashes.json"
+	path := Path(dir, "crashes.json")
 
 	// Create Core, trigger a panic through SafeGo, check crash file
 	// ErrorPanic.filePath is unexported — but we can test via the package-level

example_test.go

@@ -2,7 +2,6 @@ package core_test
 
 import (
 	"context"
-	"fmt"
 
 	. "dappco.re/go/core"
 )
@@ -14,7 +13,7 @@ func ExampleNew() {
 		WithOption("name", "my-app"),
 		WithServiceLock(),
 	)
-	fmt.Println(c.App().Name)
+	Println(c.App().Name)
 	// Output: my-app
 }
 
@@ -31,7 +30,7 @@ func ExampleNew_withService() {
 		}),
 	)
 	c.ServiceStartup(context.Background(), nil)
-	fmt.Println(c.Services())
+	Println(c.Services())
 	c.ServiceShutdown(context.Background())
 	// Output is non-deterministic (map order), so no Output comment
 }
@@ -44,9 +43,9 @@ func ExampleNewOptions() {
 		Option{Key: "port", Value: 8080},
 		Option{Key: "debug", Value: true},
 	)
-	fmt.Println(opts.String("name"))
+	Println(opts.String("name"))
-	fmt.Println(opts.Int("port"))
+	Println(opts.Int("port"))
-	fmt.Println(opts.Bool("debug"))
+	Println(opts.Bool("debug"))
 	// Output:
 	// brain
 	// 8080
@@ -58,7 +57,7 @@ func ExampleNewOptions() {
 func ExampleResult() {
 	r := Result{Value: "hello", OK: true}
 	if r.OK {
-		fmt.Println(r.Value)
+		Println(r.Value)
 	}
 	// Output: hello
 }
@@ -69,9 +68,9 @@ func ExampleCore_Action_register() {
 	c := New()
 	c.Action("greet", func(_ context.Context, opts Options) Result {
 		name := opts.String("name")
-		return Result{Value: "hello " + name, OK: true}
+		return Result{Value: Concat("hello ", name), OK: true}
 	})
-	fmt.Println(c.Action("greet").Exists())
+	Println(c.Action("greet").Exists())
 	// Output: true
 }
 
@@ -87,7 +86,7 @@ func ExampleCore_Action_invoke() {
 		Option{Key: "a", Value: 3},
 		Option{Key: "b", Value: 4},
 	))
-	fmt.Println(r.Value)
+	Println(r.Value)
 	// Output: 7
 }
 
@@ -96,7 +95,7 @@ func ExampleCore_Actions() {
 	c.Action("process.run", func(_ context.Context, _ Options) Result { return Result{OK: true} })
 	c.Action("brain.recall", func(_ context.Context, _ Options) Result { return Result{OK: true} })
 
-	fmt.Println(c.Actions())
+	Println(c.Actions())
 	// Output: [process.run brain.recall]
 }
 
@@ -123,7 +122,7 @@ func ExampleCore_Task() {
 	})
 
 	c.Task("pipeline").Run(context.Background(), c, NewOptions())
-	fmt.Println(order)
+	Println(order)
 	// Output: ab
 }
 
@@ -134,9 +133,9 @@ func ExampleNewRegistry() {
 	r.Set("alpha", "first")
 	r.Set("bravo", "second")
 
-	fmt.Println(r.Has("alpha"))
+	Println(r.Has("alpha"))
-	fmt.Println(r.Names())
+	Println(r.Names())
-	fmt.Println(r.Len())
+	Println(r.Len())
 	// Output:
 	// true
 	// [alpha bravo]
@@ -149,7 +148,7 @@ func ExampleRegistry_Lock() {
 	r.Lock()
 
 	result := r.Set("beta", "second")
-	fmt.Println(result.OK)
+	Println(result.OK)
 	// Output: false
 }
 
@@ -159,9 +158,9 @@ func ExampleRegistry_Seal() {
 	r.Seal()
 
 	// Can update existing
-	fmt.Println(r.Set("alpha", "updated").OK)
+	Println(r.Set("alpha", "updated").OK)
 	// Can't add new
-	fmt.Println(r.Set("beta", "new").OK)
+	Println(r.Set("beta", "new").OK)
 	// Output:
 	// true
 	// false
@@ -172,8 +171,8 @@ func ExampleRegistry_Seal() {
 func ExampleCore_Entitled_default() {
 	c := New()
 	e := c.Entitled("anything")
-	fmt.Println(e.Allowed)
+	Println(e.Allowed)
-	fmt.Println(e.Unlimited)
+	Println(e.Unlimited)
 	// Output:
 	// true
 	// true
@@ -188,9 +187,9 @@ func ExampleCore_Entitled_custom() {
 		return Entitlement{Allowed: true, Unlimited: true}
 	})
 
-	fmt.Println(c.Entitled("basic").Allowed)
+	Println(c.Entitled("basic").Allowed)
-	fmt.Println(c.Entitled("premium").Allowed)
+	Println(c.Entitled("premium").Allowed)
-	fmt.Println(c.Entitled("premium").Reason)
+	Println(c.Entitled("premium").Reason)
 	// Output:
 	// true
 	// false
@@ -199,8 +198,8 @@ func ExampleCore_Entitled_custom() {
 
 func ExampleEntitlement_NearLimit() {
 	e := Entitlement{Allowed: true, Limit: 100, Used: 85, Remaining: 15}
-	fmt.Println(e.NearLimit(0.8))
+	Println(e.NearLimit(0.8))
-	fmt.Println(e.UsagePercent())
+	Println(e.UsagePercent())
 	// Output:
 	// true
 	// 85
@@ -211,16 +210,16 @@ func ExampleEntitlement_NearLimit() {
 func ExampleCore_Process() {
 	c := New()
 	// No go-process registered — permission by registration
-	fmt.Println(c.Process().Exists())
+	Println(c.Process().Exists())
 
 	// Register a mock process handler
 	c.Action("process.run", func(_ context.Context, opts Options) Result {
-		return Result{Value: "output of " + opts.String("command"), OK: true}
+		return Result{Value: Concat("output of ", opts.String("command")), OK: true}
 	})
-	fmt.Println(c.Process().Exists())
+	Println(c.Process().Exists())
 
 	r := c.Process().Run(context.Background(), "echo", "hello")
-	fmt.Println(r.Value)
+	Println(r.Value)
 	// Output:
 	// false
 	// true
@@ -235,7 +234,7 @@ func ExampleJSONMarshal() {
 		Port int    `json:"port"`
 	}
 	r := JSONMarshal(config{Host: "localhost", Port: 8080})
-	fmt.Println(string(r.Value.([]byte)))
+	Println(string(r.Value.([]byte)))
 	// Output: {"host":"localhost","port":8080}
 }
 
@@ -246,7 +245,7 @@ func ExampleJSONUnmarshalString() {
 	}
 	var cfg config
 	JSONUnmarshalString(`{"host":"localhost","port":8080}`, &cfg)
-	fmt.Println(cfg.Host, cfg.Port)
+	Println(cfg.Host, cfg.Port)
 	// Output: localhost 8080
 }
 
@@ -254,15 +253,15 @@ func ExampleJSONUnmarshalString() {
 
 func ExampleID() {
 	id := ID()
-	fmt.Println(HasPrefix(id, "id-"))
+	Println(HasPrefix(id, "id-"))
 	// Output: true
 }
 
 func ExampleValidateName() {
-	fmt.Println(ValidateName("brain").OK)
+	Println(ValidateName("brain").OK)
-	fmt.Println(ValidateName("").OK)
+	Println(ValidateName("").OK)
-	fmt.Println(ValidateName("..").OK)
+	Println(ValidateName("..").OK)
-	fmt.Println(ValidateName("path/traversal").OK)
+	Println(ValidateName("path/traversal").OK)
 	// Output:
 	// true
 	// false
@@ -271,9 +270,9 @@ func ExampleValidateName() {
 }
 
 func ExampleSanitisePath() {
-	fmt.Println(SanitisePath("../../etc/passwd"))
+	Println(SanitisePath("../../etc/passwd"))
-	fmt.Println(SanitisePath(""))
+	Println(SanitisePath(""))
-	fmt.Println(SanitisePath("/some/path/file.txt"))
+	Println(SanitisePath("/some/path/file.txt"))
 	// Output:
 	// passwd
 	// invalid
@@ -286,12 +285,12 @@ func ExampleCore_Command() {
 	c := New()
 	c.Command("deploy/to/homelab", Command{
 		Action: func(opts Options) Result {
-			return Result{Value: "deployed to " + opts.String("_arg"), OK: true}
+			return Result{Value: Concat("deployed to ", opts.String("_arg")), OK: true}
 		},
 	})
 
 	r := c.Cli().Run("deploy", "to", "homelab")
-	fmt.Println(r.OK)
+	Println(r.OK)
 	// Output: true
 }
 
@@ -303,9 +302,9 @@ func ExampleConfig() {
 	c.Config().Set("database.port", 5432)
 	c.Config().Enable("dark-mode")
 
-	fmt.Println(c.Config().String("database.host"))
+	Println(c.Config().String("database.host"))
-	fmt.Println(c.Config().Int("database.port"))
+	Println(c.Config().Int("database.port"))
-	fmt.Println(c.Config().Enabled("dark-mode"))
+	Println(c.Config().Enabled("dark-mode"))
 	// Output:
 	// localhost
 	// 5432

fs_example_test.go

@@ -1,7 +1,6 @@
 package core_test
 
 import (
-	"fmt"
 
 	. "dappco.re/go/core"
 )
@@ -15,7 +14,7 @@ func ExampleFs_WriteAtomic() {
 	f.WriteAtomic(path, `{"status":"completed"}`)
 
 	r := f.Read(path)
-	fmt.Println(r.Value)
+	Println(r.Value)
 	// Output: {"status":"completed"}
 }
 
@@ -32,12 +31,12 @@ func ExampleFs_NewUnrestricted() {
 	unrestricted := sandbox.NewUnrestricted()
 
 	r := unrestricted.Read(outside)
-	fmt.Println(r.Value)
+	Println(r.Value)
 	// Output: hello
 }
 
 func ExampleFs_Root() {
 	f := (&Fs{}).New("/srv/workspaces")
-	fmt.Println(f.Root())
+	Println(f.Root())
 	// Output: /srv/workspaces
 }

i18n_test.go

@@ -75,7 +75,7 @@ type mockTranslator struct {
 }
 
 func (m *mockTranslator) Translate(id string, args ...any) Result {
-	return Result{"translated:" + id, true}
+	return Result{Concat("translated:", id), true}
 }
 func (m *mockTranslator) SetLanguage(lang string) error { m.lang = lang; return nil }
 func (m *mockTranslator) Language() string              { return m.lang }

info_example_test.go

@@ -1,18 +1,17 @@
 package core_test
 
 import (
-	"fmt"
 
 	. "dappco.re/go/core"
 )
 
 func ExampleEnv() {
-	fmt.Println(Env("OS"))   // e.g. "darwin"
+	Println(Env("OS"))   // e.g. "darwin"
-	fmt.Println(Env("ARCH")) // e.g. "arm64"
+	Println(Env("ARCH")) // e.g. "arm64"
 }
 
 func ExampleEnvKeys() {
 	keys := EnvKeys()
-	fmt.Println(len(keys) > 0)
+	Println(len(keys) > 0)
 	// Output: true
 }

lock_example_test.go

@@ -1,7 +1,6 @@
 package core_test
 
 import (
-	"fmt"
 
 	. "dappco.re/go/core"
 )
@@ -10,9 +9,9 @@ func ExampleCore_Lock() {
 	c := New()
 	lock := c.Lock("drain")
 	lock.Mutex.Lock()
-	fmt.Println("locked")
+	Println("locked")
 	lock.Mutex.Unlock()
-	fmt.Println("unlocked")
+	Println("unlocked")
 	// Output:
 	// locked
 	// unlocked

path_example_test.go

@@ -1,35 +1,34 @@
 package core_test
 
 import (
-	"fmt"
 
 	. "dappco.re/go/core"
 )
 
 func ExampleJoinPath() {
-	fmt.Println(JoinPath("deploy", "to", "homelab"))
+	Println(JoinPath("deploy", "to", "homelab"))
 	// Output: deploy/to/homelab
 }
 
 func ExamplePathBase() {
-	fmt.Println(PathBase("/srv/workspaces/alpha"))
+	Println(PathBase("/srv/workspaces/alpha"))
 	// Output: alpha
 }
 
 func ExamplePathDir() {
-	fmt.Println(PathDir("/srv/workspaces/alpha"))
+	Println(PathDir("/srv/workspaces/alpha"))
 	// Output: /srv/workspaces
 }
 
 func ExamplePathExt() {
-	fmt.Println(PathExt("report.pdf"))
+	Println(PathExt("report.pdf"))
 	// Output: .pdf
 }
 
 func ExampleCleanPath() {
-	fmt.Println(CleanPath("/tmp//file", "/"))
+	Println(CleanPath("/tmp//file", "/"))
-	fmt.Println(CleanPath("a/b/../c", "/"))
+	Println(CleanPath("a/b/../c", "/"))
-	fmt.Println(CleanPath("deploy/to/homelab", "/"))
+	Println(CleanPath("deploy/to/homelab", "/"))
 	// Output:
 	// /tmp/file
 	// a/c

process_test.go

@@ -15,7 +15,7 @@ func TestProcess_Run_Good(t *testing.T) {
 	// Register a mock process handler
 	c.Action("process.run", func(_ context.Context, opts Options) Result {
 		cmd := opts.String("command")
-		return Result{Value: "output of " + cmd, OK: true}
+		return Result{Value: Concat("output of ", cmd), OK: true}
 	})
 
 	r := c.Process().Run(context.Background(), "git", "log")
@@ -46,7 +46,7 @@ func TestProcess_RunIn_Good(t *testing.T) {
 	c.Action("process.run", func(_ context.Context, opts Options) Result {
 		dir := opts.String("dir")
 		cmd := opts.String("command")
-		return Result{Value: cmd + " in " + dir, OK: true}
+		return Result{Value: Concat(cmd, " in ", dir), OK: true}
 	})
 
 	r := c.Process().RunIn(context.Background(), "/repo", "go", "test")
@@ -126,7 +126,7 @@ func TestProcess_Ugly_PermissionByRegistration(t *testing.T) {
 	// Full Core
 	full := New()
 	full.Action("process.run", func(_ context.Context, opts Options) Result {
-		return Result{Value: "executed " + opts.String("command"), OK: true}
+		return Result{Value: Concat("executed ", opts.String("command")), OK: true}
 	})
 
 	// Sandboxed Core

registry_example_test.go

@@ -1,7 +1,6 @@
 package core_test
 
 import (
-	"fmt"
 
 	. "dappco.re/go/core"
 )
@@ -10,7 +9,7 @@ func ExampleRegistry_Set() {
 	r := NewRegistry[string]()
 	r.Set("alpha", "first")
 	r.Set("bravo", "second")
-	fmt.Println(r.Get("alpha").Value)
+	Println(r.Get("alpha").Value)
 	// Output: first
 }
 
@@ -19,7 +18,7 @@ func ExampleRegistry_Names() {
 	r.Set("charlie", 3)
 	r.Set("alpha", 1)
 	r.Set("bravo", 2)
-	fmt.Println(r.Names())
+	Println(r.Names())
 	// Output: [charlie alpha bravo]
 }
 
@@ -30,7 +29,7 @@ func ExampleRegistry_List() {
 	r.Set("brain.recall", "recall")
 
 	items := r.List("process.*")
-	fmt.Println(len(items))
+	Println(len(items))
 	// Output: 2
 }
 
@@ -42,7 +41,7 @@ func ExampleRegistry_Each() {
 
 	sum := 0
 	r.Each(func(_ string, v int) { sum += v })
-	fmt.Println(sum)
+	Println(sum)
 	// Output: 6
 }
 
@@ -54,17 +53,17 @@ func ExampleRegistry_Disable() {
 
 	var names []string
 	r.Each(func(name string, _ string) { names = append(names, name) })
-	fmt.Println(names)
+	Println(names)
 	// Output: [bravo]
 }
 
 func ExampleRegistry_Delete() {
 	r := NewRegistry[string]()
 	r.Set("temp", "value")
-	fmt.Println(r.Has("temp"))
+	Println(r.Has("temp"))
 
 	r.Delete("temp")
-	fmt.Println(r.Has("temp"))
+	Println(r.Has("temp"))
 	// Output:
 	// true
 	// false

service_example_test.go

@@ -2,7 +2,6 @@ package core_test
 
 import (
 	"context"
-	"fmt"
 
 	. "dappco.re/go/core"
 )
@@ -17,7 +16,7 @@ func ExampleServiceFor() {
 	)
 
 	svc := c.Service("cache")
-	fmt.Println(svc.OK)
+	Println(svc.OK)
 	// Output: true
 }
 
@@ -31,7 +30,7 @@ func ExampleWithService() {
 		}),
 	)
 	c.ServiceStartup(context.Background(), nil)
-	fmt.Println(started)
+	Println(started)
 	c.ServiceShutdown(context.Background())
 	// Output: true
 }
@@ -46,6 +45,6 @@ func ExampleWithServiceLock() {
 
 	// Can't register after lock
 	r := c.Service("blocked", Service{})
-	fmt.Println(r.OK)
+	Println(r.OK)
 	// Output: false
 }

string_example_test.go

@@ -1,14 +1,13 @@
 package core_test
 
 import (
-	"fmt"
 
 	. "dappco.re/go/core"
 )
 
 func ExampleContains() {
-	fmt.Println(Contains("hello world", "world"))
+	Println(Contains("hello world", "world"))
-	fmt.Println(Contains("hello world", "mars"))
+	Println(Contains("hello world", "mars"))
 	// Output:
 	// true
 	// false
@@ -16,21 +15,21 @@ func ExampleContains() {
 
 func ExampleSplit() {
 	parts := Split("deploy/to/homelab", "/")
-	fmt.Println(parts)
+	Println(parts)
 	// Output: [deploy to homelab]
 }
 
 func ExampleJoin() {
-	fmt.Println(Join("/", "deploy", "to", "homelab"))
+	Println(Join("/", "deploy", "to", "homelab"))
 	// Output: deploy/to/homelab
 }
 
 func ExampleConcat() {
-	fmt.Println(Concat("hello", " ", "world"))
+	Println(Concat("hello", " ", "world"))
 	// Output: hello world
 }
 
 func ExampleTrim() {
-	fmt.Println(Trim("  spaced  "))
+	Println(Trim("  spaced  "))
 	// Output: spaced
 }

task_example_test.go

@@ -2,7 +2,6 @@ package core_test
 
 import (
 	"context"
-	"fmt"
 
 	. "dappco.re/go/core"
 )
@@ -32,8 +31,8 @@ func ExampleTask_Run() {
 	})
 
 	r := c.Task("pipe").Run(context.Background(), c, NewOptions())
-	fmt.Println(order)
+	Println(order)
-	fmt.Println(r.Value)
+	Println(r.Value)
 	// Output:
 	// ab
 	// got:from-a
@@ -46,6 +45,6 @@ func ExampleCore_PerformAsync() {
 	})
 
 	r := c.PerformAsync("bg.work", NewOptions())
-	fmt.Println(HasPrefix(r.Value.(string), "id-"))
+	Println(HasPrefix(r.Value.(string), "id-"))
 	// Output: true
 }

utils.go

@@ -68,6 +68,13 @@ func SanitisePath(path string) string {
 
 // --- I/O ---
 
+// Println prints values to stdout with a newline. Replaces fmt.Println.
+//
+//	core.Println("hello", 42, true)
+func Println(args ...any) {
+	fmt.Println(args...)
+}
+
 // Print writes a formatted line to a writer, defaulting to os.Stdout.
 //
 //	core.Print(nil, "hello %s", "world")     // → stdout