[yehudacohen]

Adds bin/omarchy-agent-usage-muse so the agents bar widget and panel pick up Muse Code subscriptions.

• Local stats (prompts, sessions, tokens by day and model) scanned from $XDG_DATA_HOME/muse/sessions logs. Each model response is logged twice (record.quantity + model/usage lines), so only lines carrying both a model name and a usage payload are counted; string and object model shapes are merged.
• Limits stay empty, and this is now proven structural rather than just undiscovered: driving MSP end to end (serve -> initialize -> session/start -> one minimal turn) yields a live usage/changed notification plus usage/read snapshot (tier, 300-min window percent + resetsAtMs, weekly percent + resetsAtMs) matching the TUI's /usage exactly — but a fresh host answers {} until live model traffic flows through it, and nothing persists the windows (session logs, view journals/snapshots, index DB all checked). A polling collector therefore cannot fill limits without spending a model call per refresh, which costs tokens and perturbs the meter. That needs a Muse-side change (persist last-observed usage) to unlock.
• Includes test/shell.d/agent-usage-muse-scanner-test.sh and a README collector-table row.
• Verified: new scanner test passes, plus bin-style, test/cli, and all existing agent-usage scanner tests.

[dhh]

Thanks! Muse is coming in through #14040 (from #10610, which also reads the real 5-hour and weekly limits). Closing in favor of that.