config: Default() returns error

Default() now returns (*Config, error) so callers can detect TOML parse
failures rather than silently falling back to zero values.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 11 insertions, 3 deletions

diff --git a/internal/config/config.go b/internal/config/config.go
index da7f264..12adf68 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -1,6 +1,8 @@
 package config
 
 import (
+	"errors"
+	"fmt"
 	"os"
 	"path/filepath"
 )
@@ -16,8 +18,14 @@ type Config struct {
 	WebhookURL       string `toml:"webhook_url"`
 }
 
-func Default() *Config {
-	home, _ := os.UserHomeDir()
+func Default() (*Config, error) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return nil, fmt.Errorf("cannot determine home directory: %w", err)
+	}
+	if home == "" {
+		return nil, errors.New("cannot determine home directory: HOME is empty")
+	}
 	dataDir := filepath.Join(home, ".claudomator")
 	return &Config{
 		DataDir:          dataDir,
@@ -27,7 +35,7 @@ func Default() *Config {
 		MaxConcurrent:    3,
 		DefaultTimeout:   "15m",
 		ServerAddr:       ":8484",
-	}
+	}, nil
 }
 
 // EnsureDirs creates the data directory structure.