feat(api7): support extraEnvVars for file server (3.9)

[jarvis9443]

Fixes #332

3.9 line counterpart of #333.

file_server was the only deployment in the api7ee3 chart with no way to inject environment variables — dashboard, dp_manager, developer_portal and api_usage all expose extraEnvVars.

Adds file_server.extraEnvVars (default []) and renders it in file-server-deploy.yaml. The list goes through api7ee3.tplvalues.render, so entries may contain templates and valueFrom references, matching the other components. The whole env: block is guarded by the if, so the rendered Deployment is byte-identical to before when the value is left empty.

file_server:
  enabled: true
  extraEnvVars:
    - name: API7_LOG_LEVEL
      value: debug
    - name: RELEASE_NS
      value: "{{ .Release.Namespace }}"
    - name: FROM_SECRET
      valueFrom:
        secretKeyRef:
          name: my-secret
          key: token

Chart version 3.9.3 -> 3.9.4, README regenerated with helm-docs.

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 3c2b1c46-3cae-434f-a82c-1c9a6f20f9d3

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

---

_{Comment @coderabbitai help to get the list of available commands.}