feat: deprecate hcloud datacenters ... commands (#1436)

The API endpoints `GET /v1/datacenters` and `GET /v1/datacenters/{id}`
are now deprecated and will be removed after 1 Oct. 2026. After this
date, requests to these endpoints will return `HTTP 410 Gone`.

See
https://docs.hetzner.cloud/changelog#2026-06-02-datacenters-deprecated
for more details.

---------

Co-authored-by: phm07 <22707808+phm07@users.noreply.github.com>

Author: jooola

docs/reference/manual/hcloud.md

@@ -7,14 +7,25 @@ import (
 	"github.com/hetznercloud/cli/internal/state"
 )
 
+const deprecationNotice = `The 'hcloud datacenter ...' commands are deprecated and will be removed after 1 Oct. 2026.
+After this date, requests to the datacenters API endpoints will return HTTP 410 Gone.
+
+See https://docs.hetzner.cloud/changelog#2026-06-02-datacenters-deprecated for more details.
+`
+
 func NewCommand(s state.State) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:                   "datacenter",
 		Aliases:               []string{"datacenters"},
-		Short:                 "View Datacenters",
+		Short:                 "View Datacenters (deprecated)",
 		Args:                  util.Validate,
 		TraverseChildren:      true,
 		DisableFlagsInUseLine: true,
+
+		Long: deprecationNotice,
+		PersistentPreRun: func(cmd *cobra.Command, _ []string) {
+			cmd.PrintErrln("Warning: The 'datacenter' commands are deprecated. Use the 'location' commands instead.")
+		},
 	}
 	cmd.AddCommand(
 		ListCmd.CobraCommand(s),

docs/reference/manual/hcloud_datacenter.md

@@ -32,6 +32,11 @@ var DescribeCmd = base.DescribeCmd[*hcloud.Datacenter]{
 		fmt.Fprint(out, DescribeDatacenter(s.Client(), datacenter, false))
 		return nil
 	},
+	Configure: func(_ state.State, c *cobra.Command) *cobra.Command {
+		c.Short += " (deprecated)"
+		c.Long = deprecationNotice
+		return c
+	},
 }
 
 func DescribeDatacenter(client hcapi2.Client, datacenter *hcloud.Datacenter, short bool) string {

docs/reference/manual/hcloud_datacenter_describe.md

@@ -1,6 +1,9 @@
 package datacenter
 
 import (
+	"fmt"
+
+	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 
 	"github.com/hetznercloud/cli/internal/cmd/base"
@@ -35,4 +38,10 @@ var ListCmd = &base.ListCmd[*hcloud.Datacenter, schema.Datacenter]{
 	},
 
 	Schema: hcloud.SchemaFromDatacenter,
+
+	Configure: func(_ state.State, c *cobra.Command) *cobra.Command {
+		c.Short += " (deprecated)"
+		c.Long = fmt.Sprintf("%s\n%s", deprecationNotice, c.Long)
+		return c
+	},
 }