Show LLM API balances under the chat input

Key features

• Below the chat input — a compact readout in the composer's footer band (the seat under the input card, where the stats line lives) that refreshes automatically (default every 60 s) with a manual refresh link.
• Host half (lib/index.js) reads ctx.llm.listProviders() — the exact set of LLM routes configured in dsh — on every request.
• Driven by your dsh configuration — the strip shows exactly the providers registered in dsh (the Models page / llm-pi-ai settings + the built-in adapters you use).
• Configure a new LLM in dsh and it appears on the next refresh
• remove it and it disappears.