fix: Minor fixes (#1075)

A batch of small, self-contained fixes and docs/example additions.

Fixes #625 - align the example config's `force_pull` with the actual default (`false`)
Fixes #804 - return an error instead of discarding `os.UserHomeDir()` when defaulting `cache.dir`/`host.workdir_parent`
Fixes #571 - send a `gitea-runner/<version>` User-Agent on API requests
Fixes #650 - detect an `Unauthenticated` fetch response and exit the daemon with an error instead of retrying forever
Fixes #766 - add `exec --eventpath` to supply a JSON event payload file
Fixes #256 - add a `bug-report` subcommand that prints version/Go/OS-arch/CPU info
Fixes #617 - add `runner.set_act_env` (default `true`) to optionally omit the `ACT=true` env var
Fixes #635 - record a failure result (and guard a nil reusable-workflow caller) when the job `if`-expression fails to evaluate
Fixes #1005 - remove README docs for config env-var overrides that were already removed from the code
Fixes #448 - clarify in `exec --job` help that `--workflows` may be needed to disambiguate
Fixes #209 - note that `host`-labelled runners still need Docker for `docker://` actions and service containers
Fixes #757 - add a systemd service example with automatic restart
Fixes #474 - add a Kubernetes StatefulSet example that persists the `.runner` registration across reschedules
Fixes #776 - build the basic (non-dind) docker image for `linux/riscv64`
Fixes #628 - build the basic (non-dind) docker image for `linux/s390x`Reviewed-on: https://gitea.com/gitea/runner/pulls/1075
Reviewed-by: Lunny Xiao <xiaolunwen@gmail.com>

internal/app/cmd/bug_report.go

@@ -0,0 +1,31 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package cmd
+
+import (
+	"fmt"
+	"runtime"
+
+	"gitea.com/gitea/runner/internal/pkg/ver"
+
+	"github.com/spf13/cobra"
+)
+
+// loadBugReportCmd prints environment details that are useful when opening a
+// bug report, so users can paste them straight into an issue.
+func loadBugReportCmd() *cobra.Command {
+	return &cobra.Command{
+		Use:   "bug-report",
+		Short: "Print information useful when filing a bug report",
+		Args:  cobra.MaximumNArgs(0),
+		RunE: func(cmd *cobra.Command, _ []string) error {
+			w := cmd.OutOrStdout()
+			fmt.Fprintf(w, "Runner version: %s\n", ver.Version())
+			fmt.Fprintf(w, "Go version:     %s\n", runtime.Version())
+			fmt.Fprintf(w, "OS/Arch:        %s/%s\n", runtime.GOOS, runtime.GOARCH)
+			fmt.Fprintf(w, "NumCPU:         %d\n", runtime.NumCPU())
+			return nil
+		},
+	}
+}