fix(hermes): allow configured v3 agent identity

[Gout999]

Summary

Addresses #995 with a low-risk identity configuration fallback for the Hermes plugin.

initialize() now resolves team, agent, and user IDs in this order: explicit function
arguments, environment variables, then the legacy defaults. The README documents the
optional MEMORY_TENCENTDB_TEAM_ID, MEMORY_TENCENTDB_AGENT_ID, and
MEMORY_TENCENTDB_USER_ID settings and recommends configuring a migrated agt-...
agent explicitly.

This is a partial mitigation: it does not implement lazy API list/create/discovery.

Verification

• Inline import smoke test for explicit/env/default resolution
• python3 -m py_compile MemoryCore/hermes-plugin/memory/memory_tencentdb/__init__.py
• git diff --check

Signed-off-by: Gout999 gout999@users.noreply.github.com

[Maxwell-Code07]

Thank you so much for your attention and contribution! We will arrange an internal review for this PR shortly, and all feedback will be shared right here in the discussion.