fix: update memory

[zhoujh01]

Description

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

• 引入结构化 memory merge bundle（L0/L1/L2 一次返回），新增模板 openviking/prompts/templates/compression/memory_merge_bundle.yaml:1，
  并在合并逻辑中使用它 openviking/session/memory_extractor.py:315、openviking/session/compressor.py:76。
• profile 写入改为基于 merge payload 更新 abstract/content，而不是只拼接文本 openviking/session/memory_extractor.py:220、openviking/
  session/memory_extractor.py:275。
• dedup 里读取 existing abstract 更稳（优先 mem.abstract，再 fallback）openviking/session/memory_deduplicator.py:239 前后逻辑。
• 增加 LLM 请求/响应/解析日志（debug 级）openviking/session/memory_extractor.py:171、openviking/session/memory_deduplicator.py:239。
• memory extraction prompt 增加强约束与偏好粒度规则 openviking/prompts/templates/compression/memory_extraction.yaml:49、openviking/
  prompts/templates/compression/memory_extraction.yaml:101。
• examples/memory_demo.py:1 被升级为 T1~T10 的完整 memory 测试脚本（真实流水线验证）。

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