docs: add usage of select_knowledgebase in plugin development docs

[piexian]

插件文档select_knowledgebase相关过时且不完整

Modifications / 改动点

在插件配置文档中添加 select_knowledgebase 的说明（返回 list，
支持多选），并列出 AstrBot Core 内部使用的其他 _special 值供参考。

• This is NOT a breaking change. / 这不是一个破坏性变更。

Screenshots or Test Results / 运行截图或测试结果

---

Checklist / 检查清单

• 😊 If there are new features added in the PR, I have discussed it with the authors through issues/emails, etc.
  / 如果 PR 中有新加入的功能，已经通过 Issue / 邮件等方式和作者讨论过。

• 👀 My changes have been well-tested, and "Verification Steps" and "Screenshots" have been provided above.
  / 我的更改经过了良好的测试，并已在上方提供了“验证步骤”和“运行截图”。

• 🤓 I have ensured that no new dependencies are introduced, OR if new dependencies are introduced, they have been added to the appropriate locations in requirements.txt and pyproject.toml.
  / 我确保没有引入新依赖库，或者引入了新依赖库的同时将其添加到 requirements.txt 和 pyproject.toml 文件相应位置。

• 😮 My changes do not introduce malicious code.
  / 我的更改没有引入恶意代码。

Summary by Sourcery

Document additional _special field options for plugin configuration, including behavior of select_knowledgebase and other internally used values in AstrBot Core.

Documentation:

• Clarify that select_knowledgebase is a supported _special value, returning a list and supporting multi-selection for plugin configs in both English and Chinese docs.
• List additional internal _special values used by AstrBot Core to guide plugin authors beyond the most common options.

[sourcery-ai]

Hey - I've found 1 issue, and left some high level feedback:

• Since you’re now exposing internal _special values like select_providers, provider_pool, etc., consider explicitly stating whether these are stable/public or internal/subject-to-change to avoid plugin authors depending on unsupported interfaces.

Prompt for AI Agents

Please address the comments from this code review:

## Overall Comments
- Since you’re now exposing internal `_special` values like `select_providers`, `provider_pool`, etc., consider explicitly stating whether these are stable/public or internal/subject-to-change to avoid plugin authors depending on unsupported interfaces.

## Individual Comments

### Comment 1
<location path="docs/en/dev/star/guides/plugin-config.md" line_range="73" />
<code_context>
+> [!NOTE]
+> For reference, AstrBot Core also uses other internal `_special` values, such as `select_providers`, `provider_pool`, `persona_pool`, `select_plugin_set`, `t2i_template`, `get_embedding_dim`, and `select_agent_runner_provider:*`.
+
+Using `select_provider` as an example, it will present the following effect:

 ![image](https://files.astrbot.app/docs/source/images/plugin/image-select-provider.png)
</code_context>
<issue_to_address>
**suggestion (typo):** Consider rephrasing "present the following effect" to a more natural English expression.

The phrasing is understandable but slightly awkward. Consider alternatives like "it will have the following effect" or "it will display as follows" for more natural wording.

```suggestion
Using `select_provider` as an example, it will display as follows:
```
</issue_to_address>

---

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[gemini-code-assist]

Code Review

This pull request updates the plugin configuration documentation in both English and Chinese to include the select_knowledgebase special field and provides a list of internal _special values used by AstrBot Core. Feedback was provided to clarify the meaning of the wildcard in the select_agent_runner_provider:* field to prevent developer confusion.

[gemini-code-assist]

为了让文档更清晰，建议在此处说明 select_agent_runner_provider:* 中通配符 * 的含义，避免开发者产生困惑。

Suggested change

	> For reference, AstrBot Core also uses other internal `_special` values, such as `select_providers`, `provider_pool`, `persona_pool`, `select_plugin_set`, `t2i_template`, `get_embedding_dim`, and `select_agent_runner_provider:*`.
	> For reference, AstrBot Core also uses other internal `_special` values, such as `select_providers`, `provider_pool`, `persona_pool`, `select_plugin_set`, `t2i_template`, `get_embedding_dim`, and `select_agent_runner_provider:*` (where `*` is a wildcard for the agent runner subtype).

[gemini-code-assist]

为了让文档更清晰，建议在此处说明 select_agent_runner_provider:* 中通配符 * 的含义，避免开发者产生困惑。

Suggested change

	> 此外，AstrBot Core 内部还使用了 `select_providers`、`provider_pool`、`persona_pool`、`select_plugin_set`、`t2i_template`、`get_embedding_dim`、`select_agent_runner_provider:*` 等 `_special` 值，供参考。
	> 此外，AstrBot Core 内部还使用了 `select_providers`、`provider_pool`、`persona_pool`、`select_plugin_set`、`t2i_template`、`get_embedding_dim` 以及 `select_agent_runner_provider:*`（此处的 `*` 为子类型通配符）等 `_special` 值，供参考。

[Copilot]

Pull request overview

Updates the plugin configuration documentation to reflect current _special capabilities, especially select_knowledgebase, so plugin authors can rely on accurate WebUI behavior.

Changes:

• Documented select_knowledgebase under _special, including that it returns a list and supports multi-select.
• Added a reference list of additional internal/reserved _special values used/supported by AstrBot.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
docs/zh/dev/star/guides/plugin-config.md	Expands _special documentation with select_knowledgebase and a reference list of additional values.
docs/en/dev/star/guides/plugin-config.md	English equivalent of the _special documentation expansion, including select_knowledgebase.

[Copilot]

In the NOTE, it says AstrBot Core “also uses” provider_pool / persona_pool as _special values, but there are no occurrences of "_special": "provider_pool" or "_special": "persona_pool" in the repo’s config schemas (they appear to be values the Dashboard renderer supports, not necessarily ones Core actively uses). Suggest rewording to “Dashboard supports / reserved for internal use”, or cite an actual Core schema usage. Also, since select_providers is listed here, consider noting it returns a list (multi-select) to prevent misuse.

Suggested change

	> For reference, AstrBot Core also uses other internal `_special` values, such as `select_providers`, `provider_pool`, `persona_pool`, `select_plugin_set`, `t2i_template`, `get_embedding_dim`, and `select_agent_runner_provider:*`.
	> For reference, the Dashboard renderer also supports additional internal `_special` values, such as `select_providers`, `provider_pool`, `persona_pool`, `select_plugin_set`, `t2i_template`, `get_embedding_dim`, and `select_agent_runner_provider:*`. These are reserved for AstrBot's own built-in configurations and may change without notice; third-party plugins should avoid relying on them.
	> Note: `select_providers` returns a `list` (multi-select), so any schema using it must set `"type": "list"` with an appropriate list default (for example `[]`).

[Copilot]

这段 NOTE 里提到 AstrBot Core “内部还使用了” provider_pool / persona_pool 作为 _special 值，但目前仓库内未找到任何配置 schema 使用 "_special": "provider_pool" 或 "_special": "persona_pool"（它们更像是 Dashboard 已支持但未必在 Core schema 中实际引用的内部值）。建议：1) 若只是表示 WebUI 支持这些 _special，请改成“Dashboard 支持/内部保留”；或 2) 给出 Core 中实际使用它们的 schema 示例来源。另：既然在此处列出了 select_providers，建议补充其返回值也是 list（多选）以避免误用。

Suggested change

	- `select_knowledgebase` 的结果为 `list` 类型，支持多选，建议将对应配置项的 `type` 设为 `list`，默认值设为 `[]`。
	> [!NOTE]
	> 此外，AstrBot Core 内部还使用了 `select_providers`、`provider_pool`、`persona_pool`、`select_plugin_set`、`t2i_template`、`get_embedding_dim`、`select_agent_runner_provider:*` 等 `_special` 值，供参考。
	- `select_knowledgebase`、`select_providers` 的结果为 `list` 类型，支持多选，建议将对应配置项的 `type` 设为 `list`，默认值设为 `[]`。
	> [!NOTE]
	> 此外，Dashboard 内部还预留并使用了 `select_providers`、`provider_pool`、`persona_pool`、`select_plugin_set`、`t2i_template`、`get_embedding_dim`、`select_agent_runner_provider:*` 等 `_special` 值，供参考，一般插件开发者可仅关注上文列出的常用值。