Fix mutable default arguments in constructors and methods

[Copilot]

Eliminates Python anti-pattern B006 where mutable objects ([], {}) used as default parameter values cause shared state across function calls.

Changes

Fixed 6 instances across 4 files by replacing mutable defaults with None and initializing inside the function:

• astrbot/core/star/filter/command.py - CommandFilter.__init__()
• astrbot/core/platform/astr_message_event.py - request_llm() (2 parameters)
• astrbot/core/provider/sources/dashscope_source.py - text_chat()
• astrbot/core/utils/dify_api_client.py - chat_messages() and workflow_run()

Pattern Applied

# Before - shared state bug
def request_llm(self, image_urls: list[str] = [], contexts: list = []):
    return ProviderRequest(image_urls=image_urls, contexts=contexts)

# After - isolated state
def request_llm(self, image_urls: list[str] | None = None, contexts: list | None = None):
    if image_urls is None:
        image_urls = []
    if contexts is None:
        contexts = []
    return ProviderRequest(image_urls=image_urls, contexts=contexts)

No functional changes - behavior remains identical.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• api.soulter.top
  • Triggering command: /home/REDACTED/work/AstrBot/AstrBot/.venv/bin/python /home/REDACTED/work/AstrBot/AstrBot/.venv/bin/pytest tests/ -v (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

搜索项目内是否存在构造函数参数默认值为可变对象的情况，如果有，请修正。

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[LIghtJUNction]

默认值不可以用可变对象，比如list
比较详细的原因分析：【【Python】我精心设计的默认参数，怎么就出问题了呢？-哔哩哔哩】 https://b23.tv/l1j7soM

[Copilot]

Pull Request Overview

This PR refactors default parameter handling to follow Python best practices by replacing mutable default arguments (empty lists [] and [""]) with None and initializing them within the function body.

• Replaced mutable default arguments with None across multiple files
• Added initialization checks at the start of affected functions
• Applied the pattern consistently to files, image_urls, contexts, and parent_command_names parameters

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
astrbot/core/utils/dify_api_client.py	Changed files parameter defaults from [] to None in chat_messages and workflow_run methods
astrbot/core/star/filter/command.py	Changed parent_command_names parameter default from [""] to None in CommandFilter.__init__
astrbot/core/provider/sources/dashscope_source.py	Changed image_urls parameter default from [] to None in text_chat method
astrbot/core/platform/astr_message_event.py	Changed image_urls and contexts parameter defaults from [] to None in request_llm method