Fix CLI banner model label

[akseljoonas]

Summary

• load the CLI config before printing the startup banner
• pass the loaded CLI model into print_banner()
• remove the stale hardcoded Bedrock fallback label from the banner helper

Testing

• python -m compileall agent/main.py agent/utils/terminal_display.py

[claude]

Claude finished @akseljoonas's task in 57s —— View job

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PR Review: Fix CLI banner model label

• Gather context and read changed files
• Review diff and analyze correctness
• Post review findings

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LGTM
Verdict: ready to merge

What I checked

• agent/main.py reorder: load_config(CLI_CONFIG_PATH) is moved from ~line 857 (after print_banner) to ~line 834 (before it). load_config is pure file I/O + env-var substitution with no dependency on hf_token or other runtime state (agent/config.py:89-105), so moving it earlier is safe. The old config = load_config(...) block at line ~857 was removed; config is now loaded exactly once.
• print_banner call site (agent/main.py:844): config.model_name is a required str field (agent/config.py:24) — it will always be populated by load_config, so the banner will always receive a real model string, never None.
• Fallback change (agent/utils/terminal_display.py:102): "bedrock/us.anthropic.claude-opus-4-6-v1" → "unknown". This fallback now only fires if print_banner is called without an argument from some other call site, which doesn't currently exist. "unknown" is an honest sentinel; the Bedrock string was both stale and misleading.
• headless_main: unaffected — it never calls print_banner.
• Double-load risk: none — the old second load_config assignment was cleanly removed.