/personality command saves to config but doesn't affect current CLI session — ephemeral_system_prompt ignored when session DB has stored prompt #58774

Bug Description

/personality surfer in CLI shows "Personality set to 'surfer' (saved to config)" and writes to config.yaml, but the agent continues using the old personality because _restore_or_build_system_prompt() in conversation_loop.py prioritizes the session DB stored prompt over ephemeral_system_prompt.

Steps to Reproduce

1. Start CLI session: hermes chat
2. Have a conversation (creates session DB entry with system prompt)
3. Execute /personality surfer
4. System shows "Personality set to 'surfer' (saved to config)"
5. Agent continues responding in old style
6. Check config.yaml — agent.system_prompt is updated to surfer
7. Current session agent still uses old system prompt

Root Cause Analysis

_handle_personality_command()  [cli.py:8337]
  → self.system_prompt = personality_text
  → self.agent = None  (force re-init)
  → save_config_value("agent.system_prompt", ...)

_init_agent()  [cli.py:5050]
  → self.agent = AIAgent(
      ephemeral_system_prompt=self.system_prompt  ← new personality passed in
    )

conversation_loop.py:585-588
  → _restore_or_build_system_prompt(agent, ...)

conversation_loop.py:267-271  ← BUG IS HERE
  → if stored_prompt:
      agent._cached_system_prompt = stored_prompt  ← session DB wins, ephemeral ignored
      return

_restore_or_build_system_prompt() (conversation_loop.py:218) restores the old system prompt from session DB, completely ignoring the newly set ephemeral_system_prompt.

Why it worked initially (catgirl/noir): Fresh session, no stored prompt in session DB → fell through to "build from scratch" path → used ephemeral_system_prompt.

Why it fails now: Session DB has stored prompt from previous conversation → always restores old → ephemeral_system_prompt never used.

Evidence

• system_prompt.py:285-286 comments: "ephemeral_system_prompt is NOT included here. It's injected at API-call time only"
• conversation_loop.py:267-271: if stored_prompt: agent._cached_system_prompt = stored_prompt; return — no check for ephemeral
• Config currently stores pirate personality (last /personality command), but agent behavior unchanged

Suggested Fix

In conversation_loop.py, before line 267, add:

if agent.ephemeral_system_prompt:
    agent._cached_system_prompt = agent.ephemeral_system_prompt
    return

This ensures ephemeral_system_prompt takes priority over session DB stored prompt, which is the intended behavior for a personality override.

Environment

• Hermes Agent v0.18.0
• Ubuntu 24.04 (server) + macOS (client)
• CLI mode (hermes chat)