chore(runtime): Add logrus logging framework with structured logging

Add logrus as the primary logging framework with dependency injection
pattern. All errors now use WithError() for context, and structured
logging uses camelCase field names. Tag runtime service with service
field for better log organization.

- Add logrus dependency
- Update Runtime to accept logger via dependency injection
- Add WithLogger() option for logger configuration
- Log errors with WithError() for context
- Log async function failures with service context
- Document logging practices in AGENTS.md

.gitignore

@@ -1 +1,2 @@
 .opencode
+/poiesis

AGENTS.md

@@ -106,6 +106,62 @@ functions.RegisterAsyncFunction[FetchArgs, *FetchResult]("fetch", Fetch)
 - `github.com/evanw/esbuild/pkg/api` - TypeScript transpilation
 - `github.com/fastschema/qjs` - JavaScript execution (CGO-free QuickJS runtime)
 - `github.com/stretchr/testify/assert` - Test assertions
+- `github.com/sirupsen/logrus` - Logging framework
+
+## Logging Practices
+
+### Primary Logger
+
+Use `github.com/sirupsen/logrus` as the primary logging framework throughout the codebase.
+
+### Error Handling
+
+- Use `WithError(err)` when logging errors to include the error context
+- Every error should eventually be logged somewhere appropriate in the call chain
+- Don't log on every error condition - find the appropriate upstream logging location
+- Use structured logging with context fields when relevant for debugging
+
+### Structured Logging
+
+- Use `WithField(key, value)` for contextual information
+- Use `WithFields(fields)` when adding multiple fields
+- Field names must be in camelCase (e.g., `WithField("filePath", path)`)
+- Only use WithField(s) when the field is relevant and helpful for debugging issues
+- Tag services with their name: `logger.WithField("service", "runtime")`
+
+### Example Usage
+
+```go
+import "github.com/sirupsen/logrus"
+
+func New(ctx context.Context) (*Runtime, error) {
+    logger := logrus.New()
+    r := &Runtime{logger: logger.WithField("service", "runtime")}
+
+    rt, err := qjs.New(r.opts)
+    if err != nil {
+        logger.WithError(err).Error("Failed to create QuickJS context")
+        return nil, err
+    }
+
+    return r, nil
+}
+
+func (r *Runtime) ExecuteFile(filePath string) error {
+    data, err := os.ReadFile(filePath)
+    if err != nil {
+        return fmt.Errorf("read file %s: %w", filePath, err)
+    }
+
+    result, err := r.ctx.Eval("code.ts", qjs.Code(string(data)))
+    if err != nil {
+        r.logger.WithField("filePath", filePath).WithError(err).Error("Execution failed")
+        return err
+    }
+
+    return nil
+}
+```
 
 ## Code Conventions
 

cmd/poiesis/main.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 
+	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 	"reichard.io/poiesis/internal/runtime"
 )
@@ -13,23 +14,26 @@ var runCmd = &cobra.Command{
 	Use:   "execute [file]",
 	Short: "Transpile and execute TypeScript code",
 	Long: `Poiesis transpiles TypeScript to JavaScript using esbuild and executes it with QuickJS.
-It also provides a builtin system for exposing Go functions to TypeScript.`,
+	It also provides a builtin system for exposing Go functions to TypeScript.`,
 	Args: cobra.MaximumNArgs(1),
 	Run: func(cmd *cobra.Command, args []string) {
 		ctx := context.Background()
-		rt, err := runtime.New(ctx)
+		logger := logrus.New()
+		rt, err := runtime.New(ctx, runtime.WithLogger(logger))
 		if err != nil {
+			logger.WithError(err).Error("Failed to create runtime")
 			fmt.Fprintf(os.Stderr, "Failed to create runtime: %v\n", err)
 			os.Exit(1)
 		}
 
 		if len(args) == 0 {
 			fmt.Fprintln(os.Stderr, "Usage: poiesis execute [file]")
-			cmd.Help()
+			_ = cmd.Help()
 			os.Exit(1)
 		}
 
 		if err := rt.RunFile(args[0]); err != nil {
+			logger.WithError(err).Error("Failed to run file")
 			fmt.Fprintf(os.Stderr, "Failed to run file: %v\n", err)
 			os.Exit(1)
 		}
@@ -41,8 +45,10 @@ var typesCmd = &cobra.Command{
 	Short: "Print TypeScript type declarations",
 	Run: func(cmd *cobra.Command, args []string) {
 		ctx := context.Background()
-		rt, err := runtime.New(ctx)
+		logger := logrus.New()
+		rt, err := runtime.New(ctx, runtime.WithLogger(logger))
 		if err != nil {
+			logger.WithError(err).Error("Failed to create runtime")
 			fmt.Fprintf(os.Stderr, "Failed to create runtime: %v\n", err)
 			os.Exit(1)
 		}

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/sirupsen/logrus v1.9.4 // indirect
 	github.com/spf13/cobra v1.10.2 // indirect
 	github.com/spf13/pflag v1.0.9 // indirect
 	github.com/tetratelabs/wazero v1.9.0 // indirect

go.sum

@@ -10,6 +10,8 @@ github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLf
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/sirupsen/logrus v1.9.4 h1:TsZE7l11zFCLZnZ+teH4Umoq5BhEIfIzfRDZ1Uzql2w=
+github.com/sirupsen/logrus v1.9.4/go.mod h1:ftWc9WdOfJ0a92nsE2jF5u5ZwH8Bv2zdeOC42RjbV2g=
 github.com/spf13/cobra v1.10.2 h1:DMTTonx5m65Ic0GOoRY2c16WCbHxOOw6xxezuLaBpcU=
 github.com/spf13/cobra v1.10.2/go.mod h1:7C1pvHqHw5A4vrJfjNwvOdzYu0Gml16OCs2GRiTUUS4=
 github.com/spf13/pflag v1.0.9 h1:9exaQaMOCwffKiiiYk6/BndUBv+iRViNW+4lEMi0PvY=

internal/runtime/options.go

@@ -1,6 +1,10 @@
 package runtime
 
-import "io"
+import (
+	"io"
+
+	"github.com/sirupsen/logrus"
+)
 
 type RuntimeOption func(*Runtime)
 
@@ -17,3 +21,9 @@ func WithStderr(stderr io.Writer) RuntimeOption {
 		r.opts.Stderr = stderr
 	}
 }
+
+func WithLogger(logger *logrus.Logger) RuntimeOption {
+	return func(r *Runtime) {
+		r.logger = logger.WithField("service", "runtime")
+	}
+}

internal/runtime/runtime.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/evanw/esbuild/pkg/api"
 	"github.com/fastschema/qjs"
+	"github.com/sirupsen/logrus"
 
 	"reichard.io/poiesis/internal/functions"
 	_ "reichard.io/poiesis/internal/stdlib"
@@ -18,11 +19,13 @@ type Runtime struct {
 	opts      qjs.Option
 	funcs     map[string]functions.Function
 	typeDecls map[string]string
+	logger    *logrus.Entry
 }
 
 func New(ctx context.Context, opts ...RuntimeOption) (*Runtime, error) {
 	// Create Runtime
-	r := &Runtime{opts: qjs.Option{Context: ctx}}
+	logger := logrus.New()
+	r := &Runtime{opts: qjs.Option{Context: ctx}, logger: logger.WithField("service", "runtime")}
 	for _, opt := range opts {
 		opt(r)
 	}
@@ -30,12 +33,14 @@ func New(ctx context.Context, opts ...RuntimeOption) (*Runtime, error) {
 	// Create QuickJS Context
 	rt, err := qjs.New(r.opts)
 	if err != nil {
+		logger.WithError(err).Error("Failed to create QuickJS context")
 		return nil, err
 	}
 	r.ctx = rt.Context()
 
 	// Populate Globals
 	if err := r.populateGlobals(); err != nil {
+		logger.WithError(err).Error("Failed to populate globals")
 		return nil, err
 	}
 
@@ -62,6 +67,7 @@ func (r *Runtime) populateGlobals() error {
 			r.ctx.SetAsyncFunc(name, func(this *qjs.This) {
 				qjsVal, err := callFunc(this, fn)
 				if err != nil {
+					r.logger.WithError(err).Errorf("Async function %s failed", name)
 					_ = this.Promise().Reject(this.Context().NewError(err))
 					return
 				}