feat(sdk): sync go/ts/python SDKs with server find/search, recall, an…

[zhoujh01]

…d admin changes

Server-side changes recently landed that the language SDKs had drifted from:

• find/search results now return tags and no longer return category/match_reason/relations/overview (feat(search): expose tags in find/search results and drop empty fields #3730). Go's strict struct was the only one broken; update MatchedContext accordingly.
• new admin endpoints for agent-evolution and per-account settings (feat(agent-evolution): improve provenance, history, and account settings #3695).
• public search/recall endpoint was missing from all SDKs.

Changes:

• python: add level/since/until/time_field to find/search; add an extra escape hatch to find/search/add_resource/write/batch_write so new server fields can be passed without an SDK bump (only forwarded when set, preserving level=0); add recall and the four admin methods.
• go: fix MatchedContext (add Tags, drop removed fields), add Recall and the four admin methods.
• typescript: type MatchedContext/FindResult, add RecallOptions, add recall and the four admin methods.

Description

Human Involvement

• A human participated in the implementation or review loop
• This PR was generated entirely by AI agents without human participation in the loop

Related Issue

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactoring (no functional changes)
• Performance improvement
• Test update

Changes Made

Testing

• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have tested this on the following platforms:
  • Linux
  • macOS
  • Windows

Checklist

• My code follows the project's coding style
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published

Screenshots (if applicable)

Additional Notes

[ZaynJarvis]

跨语言 SDK 的 session message 序列化需要保持一致；当前 Python 与 Go/TypeScript 对空 parts 的行为不同。

[ZaynJarvis]

[Bug] (blocking) parts=[] 会被当成结构化内容并删除 content，与 Go/TypeScript 的行为不一致。

例如 add_message("s", {"role": "assistant", "content": "x", "parts": []}) 在这里最终发出 {"role": "assistant", "parts": []}；Go 和 TS 都把空数组视为未提供 parts，发出 {"role": "assistant", "content": "x"}。同一个跨语言 SDK 调用会得到不同的服务端消息语义。请统一空 parts 的规则；如果 Python 有意保留这个不同语义，请说明兼容性约束。