feat(gateway): add model and provider info to /status command

[brucenewup]

What does this PR do?

Adds model name and provider information to the gateway /status command output, with real-time session override support.

Key improvement: When you switch models with /model, /status immediately shows the new model instead of the global config. This brings /status to parity with /new and /reset commands.

Related Issue

N/A - Small UX enhancement to help gateway users quickly verify their active model configuration.

Changes Made

• Read model config from config.yaml in _handle_status_command()
• Check session-specific model overrides (same logic as /model command)
• Display "Model: {name}" and "Provider: {provider}" in status output
• Graceful error handling with fallback to "unknown" / "auto"

How to Test

1. Start gateway: hermes gateway start
2. Send /status → verify shows current model/provider
3. Switch model: /model minimax/MiniMax-M2.7
4. Send /status again → verify shows MiniMax-M2.7 (not global config)
5. Test error handling: rename config.yaml → verify shows "unknown"/"auto" without crash

Checklist

Code

• Read Contributing Guide
• Conventional Commits format
• Searched existing PRs
• Only related changes
• Tested on macOS
• Session override feature verified working

Documentation

• No README/docs changes needed (output-only change)
• No new config keys
• No architecture changes
• Cross-platform compatible (pathlib, YAML)
• No tool schema changes

Screenshots

Before:

📊 Hermes Gateway Status

Session ID: 20260417_045547_94fbb370
Created: 2026-04-17 04:55
Last Activity: 2026-04-17 05:09
Tokens: 0
Agent Running: No

Connected Platforms: telegram, weixin

After (global config):

📊 Hermes Gateway Status

Session ID: 20260417_045547_94fbb370
Created: 2026-04-17 04:55
Last Activity: 2026-04-17 05:09
Tokens: 0
Agent Running: No
Model: claude-sonnet-4-6
Provider: anthropic

Connected Platforms: telegram, weixin

After model switch (session override):

📊 Hermes Gateway Status

Session ID: 20260417_045547_94fbb370
Created: 2026-04-17 04:55
Last Activity: 2026-04-17 05:09
Tokens: 0
Agent Running: No
Model: MiniMax-M2.7
Provider: minimaxi.com

Connected Platforms: telegram, weixin

[alt-glitch]

Related to #6750 and #8240 — all add model/provider info to /status output. Consider consolidating.

[teknium1]

Thanks for identifying the session-switch status gap. The current gateway status implementation already restores model/provider output, but the exact immediate post-/model case remains incomplete.

Problems

• Current /status resolves from live/cached agent state, then SessionDB/config (gateway/slash_commands.py:550-610), but /model stores its selected provider in _session_model_overrides and evicts the cached agent (gateway/slash_commands.py:1867-1891). Since update_session_model() writes only sessions.model (hermes_state.py:2363-2375), a cross-provider session switch can show the new model with a stale provider.
• The handler has moved from gateway/run.py to gateway/slash_commands.py in 619bd782738adfa87544d0fda7a1114defe86e4c, so this needs a targeted port rather than a clean cherry-pick.
• tests/gateway/test_status_command.py:180-275 lacks a /model → immediate /status cross-provider regression case.

Suggested changes

• Port the override lookup into GatewaySlashCommandsMixin._handle_status_command, preserving its live-agent-first behavior and localized t("gateway.status.model_provider", ...) rendering at gateway/slash_commands.py:605-610.
• Add the immediate post-switch regression test, including an evicted cached agent.

Automated hermes-sweeper review.