fix(hermes): inject recalled context into system prompt

[YOMXXX]

Summary

• have Hermes system_prompt_block fetch recall context from the Gateway when available
• append recalled persona/scene memory context to the static memory guide so L3 persona can reach the agent system prompt
• fall back to the static block and trigger existing recovery handling when recall fails
• add a unittest covering persona context injection

Closes #205

Test plan

• python3 hermes-plugin/memory/memory_tencentdb/tests/test_system_prompt_block.py
• python3 -m py_compile hermes-plugin/memory/memory_tencentdb/init.py hermes-plugin/memory/memory_tencentdb/tests/test_system_prompt_block.py
• npm test
• npm run build

Notes

• python3 -m pytest is unavailable in this local environment: No module named pytest. The added test uses stdlib unittest and is pytest-discoverable.
• npm run test:cc-plugin -- --run currently fails because package.json has no test:cc-plugin script.

[Maxwell-Code07]

Awesome work! 13 fixes in one batch covering Gateway hardening, embedding compatibility, Hermes memory injection, offload stability, and pipeline optimization — a very productive cleanup session 👏

We'll review and merge them one by one 🚀