korg: add userinfo command for org and OWNERS lookup

Adds `korg userinfo <user>...` to answer the recurring question this repo
exists for: which Kubernetes orgs is a user in, with what role, and where
do they appear in OWNERS files.

Sources:
- GitHub user API for company / profile
- config/<org>/org.yaml (Members / Admins) for k8s org membership
- cs.k8s.io (hound) for OWNERS / OWNERS_ALIASES references

Behavior:
- Honors GITHUB_TOKEN / GH_TOKEN to avoid the 60/hr unauth limit. GitHub
  and hound use separate http.Client instances, so the token is never
  sent to cs.k8s.io
- Per-request context with a 30s timeout; SIGINT cancels in flight
- Multi-user batches run concurrently (errgroup, bounded to 4) with
  output preserved in input order
- One bad username does not kill the batch; per-user errors render in
  both text and JSON output, and the process exits non-zero
- Hound failures degrade to a warning instead of dropping org info
- `--output json` for scripting

OWNERS matching:
- Anchors the hound query on "- <user>" and keeps a hit only when the
  YAML list item equals the username exactly, so prose mentions,
  commented-out entries and substring near-misses ("- alice-bot" for
  "alice") are all dropped. Surrounding quotes and trailing inline
  comments are stripped first, so `- "alice"` and "- alice # area expert"
  still match
- Each surviving hit is confirmed against the file's real content via
  `gh api` to exclude emeritus-only entries, toggled by --verify-owners.
  A hit that cannot be fetched is kept with a warning rather than dropped
- Results render as an aligned REPO / PATH / URL table; the URL uses
  /blob/HEAD/ so the link resolves to the default branch

Tests:
- Table-driven coverage of the OWNERS match filter (quoted values, inline
  comments, commented-out entries, substring near-misses), emeritus
  exclusion, and the fail-open path when a hit cannot be verified
- Batch coverage for both output modes: input ordering, mixed
  success/failure runs, and the text renderer's company / orgs fallbacks
- Asserts hound requests carry no Authorization header while GitHub
  requests stay authenticated

Dependencies:
- adds github.com/google/go-github/v88 for the user API
- promotes golang.org/x/sync from indirect v0.2.0 to direct v0.8.0 for
  errgroup
- go directive 1.22.4 -> 1.25.0

Signed-off-by: Nabarun Pal <pal.nabarun95@gmail.com>

Author: palnabarun

cmd/korg/korg.go

@@ -17,10 +17,13 @@ limitations under the License.
 package main
 
 import (
+	"context"
 	"fmt"
 	"os"
+	"os/signal"
 	"path/filepath"
 	"strings"
+	"syscall"
 
 	"github.com/spf13/cobra"
 )
@@ -58,6 +61,27 @@ Note: Removing from teams is currently unsupported.
 	`
 
 	auditHelpText = "Audit GitHub org members"
+
+	userinfoHelpText = `
+Gets k8s org membership, GitHub profile, and OWNERS file references for user(s).
+
+Honors GITHUB_TOKEN / GH_TOKEN for authenticated GitHub API access.
+
+A failed per-user lookup does not omit that user from the output: in text mode
+it renders an ERROR block, and in JSON mode it appears with only "username"
+and "error" populated. Check the exit code to detect any failures.
+
+By default, each OWNERS/OWNERS_ALIASES hit is confirmed against the file's
+actual content (via the gh CLI) to exclude emeritus-only entries; this costs
+one "gh api" call per hit and requires the gh CLI to be installed and
+authenticated. Pass --verify-owners=false to skip this and use hound's raw
+search hits as-is.
+
+	korg userinfo <github username>
+	korg userinfo <github username1> <github username2> <github username3> ...
+	korg userinfo --output json <github username>
+	korg userinfo --verify-owners=false <github username>
+	`
 )
 
 type Options struct {
@@ -222,7 +246,32 @@ func main() {
 	rootCmd.AddCommand(removeCmd)
 	rootCmd.AddCommand(auditCmd)
 
-	if err := rootCmd.Execute(); err != nil {
+	var (
+		outputFormat string
+		verifyOwners bool
+	)
+	userInfoCmd := &cobra.Command{
+		Use:   "userinfo",
+		Short: "Get information about user(s)",
+		Long:  userinfoHelpText,
+		Args:  cobra.MinimumNArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			switch outputFormat {
+			case "text", "json":
+			default:
+				return fmt.Errorf("invalid --output %q (want: text, json)", outputFormat)
+			}
+			return runUserinfo(cmd.Context(), o.RepoRoot, args, outputFormat == "json", verifyOwners, cmd.OutOrStdout())
+		},
+	}
+	userInfoCmd.Flags().StringVarP(&outputFormat, "output", "o", "text", "output format: text|json")
+	userInfoCmd.Flags().BoolVar(&verifyOwners, "verify-owners", true, "confirm each OWNERS/OWNERS_ALIASES hit via the gh CLI and exclude emeritus-only entries; requires gh to be installed and authenticated")
+	rootCmd.AddCommand(userInfoCmd)
+
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+
+	if err := rootCmd.ExecuteContext(ctx); err != nil {
 		os.Exit(1)
 	}
 }