blocked(usage-hub): Open Design quota instrumentation — laptop sign-in, cookie capture, parser verification #1054

Part of epic #1047. BLOCKED ON DREW (one laptop sign-in).

Open Design quota is uninstrumented on the hub: the provider exists (openchamber #475, merged) but the billing/usage breakdown needs a Better Auth session cookie + workspaceId, and the API key alone gets 401.

Established 2026-10-26: a live session exists in the SANDBOX browser (workspace "Drewry Pope's workspace", id s61ob3wnph3uehnqs9wgqczj, Go plan; read 2026-10-26 04:53 CDT: 5h 0/50,000 credits, 7d 461/150,000; expires 2026-11-02) but it is UNEXTRACTABLE — the runtime browser profile is sealed from agent tooling.

Unblock (Drew, ~2 min): sign in once at open-design.ai/cloud/login in a LAPTOP browser. Then Muse: extract the cookie from the laptop profile (read path proven 2026-10-25), verify via get-session, store as ~/.config/openchamber/quota/opendesign.json (0600) = {"cookie": "better-auth.session_token=", "workspaceId": "s61ob3wnph3uehnqs9wgqczj"}, and tighten the per-model breakdown parser against the first live payload (endpoint wants ?from=&to=; field spellings unverified; parser currently fails closed).
Acceptance: Open Design card on /quota shows real 5h/7d % with measured-at; breakdown (tokens x multiplier = credits, share) renders; cookie refresh path documented in the quota registry.