fix(helm): namespace app-specific global values under global.seaweedfs (#8700)

* fix(helm): namespace app-specific values under global.seaweedfs

Move all app-specific values from the global namespace to
global.seaweedfs.* to avoid polluting the shared .Values.global
namespace when the chart is used as a subchart.

Standard Helm conventions (global.imageRegistry, global.imagePullSecrets)
remain at the global level as they are designed to be shared across
subcharts.

Fixes seaweedfs/seaweedfs#8699

BREAKING CHANGE: global values have been restructured. Users must update
their values files to use the new paths:
- global.registry → global.imageRegistry
- global.repository → global.seaweedfs.image.repository
- global.imageName → global.seaweedfs.image.name
- global.<key> → global.seaweedfs.<key> (for all other app-specific values)

* fix(ci): update helm CI tests to use new global.seaweedfs.* value paths

Update all --set flags in helm_ci.yml to use the new namespaced
global.seaweedfs.* paths matching the values.yaml restructuring.

* fix(ci): install Claude Code via npm to avoid install.sh 403

The claude-code-action's built-in installer uses
`curl https://claude.ai/install.sh | bash` which can fail with 403.
Due to the pipe, bash exits 0 on empty input, masking the curl failure
and leaving the `claude` binary missing.

Work around this by installing Claude Code via npm before invoking the
action, and passing the executable path via path_to_claude_code_executable.

* revert: remove claude-code-review.yml changes from this PR

The claude-code-action OIDC token exchange validates that the workflow
file matches the version on the default branch. Modifying it in a PR
causes the review job to fail with "Workflow validation failed".

The Claude Code install fix will need to be applied directly to master
or in a separate PR.

* fix: update stale references to old global.* value paths

- admin-statefulset.yaml: fix fail message to reference
  global.seaweedfs.masterServer
- values.yaml: fix comment to reference image.name instead of imageName
- helm_ci.yml: fix diagnostic message to reference
  global.seaweedfs.enableSecurity

* feat(helm): add backward-compat shim for old global.* value paths

Add _compat.tpl with a seaweedfs.compat helper that detects old-style
global.* keys (e.g. global.enableSecurity, global.registry) and merges
them into the new global.seaweedfs.* namespace.

Since the old keys no longer have defaults in values.yaml, their
presence means the user explicitly provided them. The helper uses
in-place mutation via `set` so all templates see the merged values.

This ensures existing deployments using old value paths continue to
work without changes after upgrading.

* fix: update stale comment references in values.yaml

Update comments referencing global.enableSecurity and global.masterServer
to the new global.seaweedfs.* paths.

---------

Co-authored-by: Copilot <copilot@github.com>

k8s/charts/seaweedfs/templates/shared/_helpers.tpl

@@ -143,9 +143,9 @@ Inject extra environment vars in the format key:value, if populated
 
 {{/* Computes the container image name for all components (if they are not overridden) */}}
 {{- define "common.image" -}}
-{{- $registryName := default .Values.image.registry .Values.global.registry | toString -}}
-{{- $repositoryName := default .Values.image.repository .Values.global.repository | toString -}}
-{{- $name := .Values.global.imageName | toString -}}
+{{- $registryName := default .Values.image.registry .Values.global.imageRegistry | toString -}}
+{{- $repositoryName := default .Values.image.repository .Values.global.seaweedfs.image.repository | toString -}}
+{{- $name := .Values.global.seaweedfs.image.name | toString -}}
 {{- $tag := default .Chart.AppVersion .Values.image.tag  | toString -}}
 {{- if .Values.image.repository -}}
 {{-   $name = $repositoryName -}}
@@ -318,8 +318,8 @@ Generate master server argument value, using global.masterServer if set, otherwi
 Usage: {{ include "seaweedfs.masterServerArg" . }}
 */}}
 {{- define "seaweedfs.masterServerArg" -}}
-{{- if .Values.global.masterServer -}}
-{{- .Values.global.masterServer -}}
+{{- if .Values.global.seaweedfs.masterServer -}}
+{{- .Values.global.seaweedfs.masterServer -}}
 {{- else -}}
 {{- include "seaweedfs.masterServers" . -}}
 {{- end -}}
@@ -329,7 +329,7 @@ Usage: {{ include "seaweedfs.masterServerArg" . }}
 Create the name of the service account to use
 */}}
 {{- define "seaweedfs.serviceAccountName" -}}
-{{- .Values.global.serviceAccountName | default "seaweedfs" -}}
+{{- .Values.global.seaweedfs.serviceAccountName | default "seaweedfs" -}}
 {{- end -}}
 
 {{/* S3 TLS cert/key arguments, using custom secret if s3.tlsSecret is set */}}