feat: auto-generate deprecation warning box from YAML config

[chaptersix]

Summary

• Add deprecated: true field to command YAML config to auto-generate CAUTION deprecation box
• Add optional deprecation-message field for custom deprecation messages
• Remove need to manually add deprecation warning boxes to command descriptions

Usage

# Default message: "This command is deprecated and will be removed in a later release."
- name: temporal some-command
  deprecated: true
  description: |
    Command description here...

# Custom message
- name: temporal other-command
  deprecated: true
  deprecation-message: This API has been deprecated by Worker Deployment.
  description: |
    Command description here...

Test plan

• Unit tests for generateDeprecationBox() function
• Verified code generation produces correct output
• All existing tests pass

Closes #673

[chaptersix]

Before/after samples

1. Cobra Command.Deprecated — deprecation warning printed to stdout

Before (old behavior using s.Command.Deprecated): Cobra prints a warning line to stdout when the command is invoked, contaminating JSON output:

$ temporal task-queue get-build-id-reachability --task-queue foo --build-id bar -o json
Command "get-build-id-reachability" is deprecated, This command is deprecated and will be removed in a later release.
Error: failed reaching server: ...

After (this PR — s.Command.Deprecated is never set): no warning on stdout, deprecation notice only appears in --help:

$ temporal task-queue get-build-id-reachability --task-queue foo --build-id bar -o json
Error: failed reaching server: ...

---

2. Deprecation box in --help

Before (manually written in YAML):

- name: temporal task-queue get-build-id-reachability
  summary: Show Build ID availability (Deprecated)
  description: |
    ```
    +-----------------------------------------------------------------------------+
    | CAUTION: This command is deprecated and will be removed in a later release. |
    +-----------------------------------------------------------------------------+
    ```

    Show if a given Build ID can be used for new, existing, or closed Workflows...

After (this PR — deprecated: true auto-generates the box):

- name: temporal task-queue get-build-id-reachability
  summary: Show Build ID availability (Deprecated)
  deprecated: true
  description: |
    Show if a given Build ID can be used for new, existing, or closed Workflows...

Rendered --help output (same in both cases):

$ temporal task-queue get-build-id-reachability --help
```
+-----------------------------------------------------------------------------+
| CAUTION: This command is deprecated and will be removed in a later release. |
+-----------------------------------------------------------------------------+
```

Show if a given Build ID can be used for new, existing, or closed Workflows
in Namespaces that support Worker versioning:
...

Custom message via deprecation-message:

- name: temporal task-queue versioning
  deprecated: true
  deprecation-message: This API has been deprecated by Worker Deployment.

$ temporal task-queue versioning --help
```
+-------------------------------------------------------------+
| CAUTION: This API has been deprecated by Worker Deployment. |
+-------------------------------------------------------------+
```

Provides commands to add, list, remove, or replace Worker Build ID assignment...