Fix errcheck lint findings in config, docker, and gitea

Handle Fprintf/Close/RemoveAll return values so golangci-lint passes.

Claude-Session: https://claude.ai/code/session_015ur3i7D2azsMAWTSVABApv

internal/cli/config.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"strings"
 
 	"github.com/spf13/cobra"
 
@@ -36,9 +37,10 @@ func newConfigInitCmd() *cobra.Command {
 			if err := os.WriteFile(path, []byte(config.Example), 0o644); err != nil {
 				return err
 			}
-			fmt.Fprintf(cmd.OutOrStdout(), "wrote example config to %s\n", path)
-			fmt.Fprintln(cmd.OutOrStdout(), "edit it, then create the referenced tea config files with `tea logins add`.")
-			return nil
+			_, err := fmt.Fprintf(cmd.OutOrStdout(),
+				"wrote example config to %s\nedit it, then create the referenced tea config files with `tea logins add`.\n",
+				path)
+			return err
 		},
 	}
 	cmd.Flags().BoolVar(&force, "force", false, "overwrite an existing config file")
@@ -54,30 +56,32 @@ func newConfigShowCmd() *cobra.Command {
 			if err != nil {
 				return err
 			}
-			out := cmd.OutOrStdout()
-			fmt.Fprintf(out, "config:         %s\n", configPath)
-			fmt.Fprintf(out, "gitea_url:      %s\n", cfg.GiteaURL)
-			fmt.Fprintf(out, "state_dir:      %s\n", cfg.StateDirOrDefault())
-			fmt.Fprintf(out, "poll_interval:  %s\n", cfg.PollInterval)
-			fmt.Fprintf(out, "job_timeout:    %s\n", cfg.JobTimeout)
-			fmt.Fprintf(out, "max_concurrent: %d\n", cfg.MaxConcurrent)
-			fmt.Fprintf(out, "job_image:      %s\n", cfg.JobImage)
-			fmt.Fprintf(out, "claude_config:  %s\n", cfg.ClaudeConfigDir)
+			lines := []string{
+				fmt.Sprintf("config:         %s", configPath),
+				fmt.Sprintf("gitea_url:      %s", cfg.GiteaURL),
+				fmt.Sprintf("state_dir:      %s", cfg.StateDirOrDefault()),
+				fmt.Sprintf("poll_interval:  %s", cfg.PollInterval),
+				fmt.Sprintf("job_timeout:    %s", cfg.JobTimeout),
+				fmt.Sprintf("max_concurrent: %d", cfg.MaxConcurrent),
+				fmt.Sprintf("job_image:      %s", cfg.JobImage),
+				fmt.Sprintf("claude_config:  %s", cfg.ClaudeConfigDir),
+			}
 			if cfg.AnthropicBaseURL != "" {
-				fmt.Fprintf(out, "anthropic_base_url: %s\n", cfg.AnthropicBaseURL)
+				lines = append(lines, "anthropic_base_url: "+cfg.AnthropicBaseURL)
 			}
 			if cfg.AnthropicAPIKey != "" {
-				fmt.Fprintf(out, "anthropic_api_key: (set)\n")
+				lines = append(lines, "anthropic_api_key: (set)")
 			}
-			fmt.Fprintf(out, "repos:\n")
+			lines = append(lines, "repos:")
 			for _, r := range cfg.Repos {
-				fmt.Fprintf(out, "  - %s\n", r)
+				lines = append(lines, "  - "+r)
 			}
-			fmt.Fprintf(out, "personalities:\n")
+			lines = append(lines, "personalities:")
 			for _, p := range cfg.Personalities {
-				fmt.Fprintf(out, "  - %s (role=%s, login=%s)\n", p.Name, p.Role, p.Login)
+				lines = append(lines, fmt.Sprintf("  - %s (role=%s, login=%s)", p.Name, p.Role, p.Login))
 			}
-			return nil
+			_, err = fmt.Fprintln(cmd.OutOrStdout(), strings.Join(lines, "\n"))
+			return err
 		},
 	}
 }

internal/docker/docker.go

@@ -69,7 +69,7 @@ func (r *DockerRunner) Run(ctx context.Context, job Job) (Result, error) {
 	if err != nil {
 		return Result{}, err
 	}
-	defer os.RemoveAll(jobDir)
+	defer func() { _ = os.RemoveAll(jobDir) }()
 
 	if job.Timeout > 0 {
 		var cancel context.CancelFunc
@@ -233,7 +233,7 @@ func copyFile(src, dst string) error {
 	if err != nil {
 		return err
 	}
-	defer in.Close()
+	defer func() { _ = in.Close() }()
 	if err := os.MkdirAll(filepath.Dir(dst), 0o700); err != nil {
 		return err
 	}
@@ -241,11 +241,12 @@ func copyFile(src, dst string) error {
 	if err != nil {
 		return err
 	}
-	defer out.Close()
 	if _, err := io.Copy(out, in); err != nil {
+		_ = out.Close()
 		return err
 	}
-	return nil
+	// Close explicitly (not deferred) so a flush error surfaces to the caller.
+	return out.Close()
 }
 
 // copyTree recursively copies a directory tree (regular files, dirs, and

internal/gitea/client.go

@@ -47,7 +47,7 @@ func (c *Client) get(ctx context.Context, path string, query url.Values, out any
 	if err != nil {
 		return fmt.Errorf("GET %s: %w", path, err)
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 	body, _ := io.ReadAll(resp.Body)
 	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
 		return fmt.Errorf("GET %s: status %d: %s", path, resp.StatusCode, strings.TrimSpace(string(body)))
@@ -194,7 +194,7 @@ func (c *Client) GetPullDiff(ctx context.Context, repo string, index int64) (str
 	if err != nil {
 		return "", err
 	}
-	defer resp.Body.Close()
+	defer func() { _ = resp.Body.Close() }()
 	body, _ := io.ReadAll(resp.Body)
 	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
 		return "", fmt.Errorf("GET pull diff: status %d", resp.StatusCode)