refactor(oocana): move string_hash to internal.py

[leavesster]

Summary

• Move string_hash() function from context.py to internal.py
• Keep utility functions in a central location

Problem

string_hash() was defined at module level in context.py but is a general utility function that doesn't belong there.

Solution

Move to internal.py where other utility functions like random_string() are defined.

Test Plan

• All existing tests pass
• Import updated in context.py

[coderabbitai]

Walkthrough

将 string_hash 函数从 context.py 迁移到 internal.py 模块。context.py 现在导入该函数，而 internal.py 中新增该函数实现，使用 SHA-256 算法生成输入字符串的十六进制摘要。

Changes

Cohort / File(s)	Summary
String hash refactoring oocana/oocana/context.py, oocana/oocana/internal.py	将 string_hash 函数从 context.py 移至 internal.py。context.py 现从 internal 模块导入该函数；internal.py 新增 string_hash(text: str) -> str 函数，返回输入字符串的 SHA-256 十六进制摘要。

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

🚥 Pre-merge checks | ✅ 2

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description check	✅ Passed	PR描述与变更集高度相关，清楚地说明了问题、解决方案和测试计划，与代码改动相符。
Title check	✅ Passed	PR title follows the required format with type(scope): subject pattern and clearly describes the main refactoring change.

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[Copilot]

Pull request overview

This PR refactors the codebase by moving the string_hash() utility function from context.py to internal.py, where other utility functions are centralized. This improves code organization by grouping utility functions together.

Changes:

• Moved string_hash() function definition from context.py to internal.py
• Updated import in context.py to import string_hash from internal
• Removed unused hashlib import from context.py

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
oocana/oocana/internal.py	Added string_hash() function definition and hashlib import
oocana/oocana/context.py	Removed string_hash() definition and hashlib import; updated import statement to include string_hash from internal

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[Copilot]

The string_hash function is placed before the InternalAPI class, but the existing random_string utility function is defined after the class (line 40). For consistency, consider moving string_hash to after the InternalAPI class definition, near random_string, to keep all utility functions grouped together.