[BUG] Desktop context ring shows no monthly budget spend for Enterprise plan seats

**Description**

Clicking the context ring in the bottom-right corner of Claude Code Desktop opens a popover. On a personal Pro/Max account, this popover shows, inline, with no further navigation:

1. "Context window" (e.g. "125.5k / 1M (13%)")
2. A "Plan usage limits · " section with:
- 5-hour limit (%)
- Weekly · all models (% + reset time)
- Usage credits ($X of $Y)

On an Enterprise plan seat, the popover only shows the "Context window" line and a "See detailed breakdown" link. The actual usage data *does* exist — clicking through to Settings surfaces a "Your usage limits · Enterprise" view showing spend vs. the org's monthly limit (e.g. "$4,411.85 of $5,000.00 spent · 88% used · Resets Mon, Aug 31, 6:00 PM MDT") — but it takes several extra clicks to get there instead of appearing inline in the popover.

I believe this used to show inline for Enterprise seats (spend vs. monthly limit, right in the popover) and stopped at some point — I don't have an exact version/date for when it changed, just recollection that it worked before. Flagging as a possible regression rather than a feature that never existed, in case that's useful for tracking down when it broke.

This matches/relates to prior reports:
- #52838 (Enterprise usage bar support) — closed as not planned on 2026-05-29
- #45079 (Desktop Code tab: No context window usage display) — closed as not planned on 2026-06-05
- #82481 (Pull Enterprise Org Spend-Limit Data in Claude Code (CLI/statusLine)) — same gap, framed as a feature request
- #84443 (`/api/oauth/usage` returns null spend/extra_usage for Enterprise orgs with per-member monthly spend limits — no parity with claude.ai Usage UI) — likely the actual root cause: if the API the popover reads from returns null for Enterprise orgs, that would explain why the popover has nothing to show here even though Settings displays the same data via a different path

Both #52838 and #45079 were closed as "not planned," but the underlying gap is still present as of the version below, and other users report seeing the same thing.

**Environment**
- Claude Code version: 2.1.235
- Client: Desktop app (macOS)
- Plan: Enterprise (org-level monthly spend limit, not the 5-hour/weekly cadence Pro/Max use)

**Expected behavior**
Clicking the context ring shows an inline usage-limits section for Enterprise (spend vs. monthly limit, reset date), matching how Pro/Max show their limits inline, instead of requiring navigation to Settings.

**Actual behavior**
Only "Context window" and "See detailed breakdown" appear in the popover. The actual spend-vs-limit data only appears after clicking through to Settings → Usage limits.

**Screenshots**
- Pro account popover (inline): Context window + "Plan usage limits · Pro" (5-hour limit 0%, Weekly all models 11% resets Thu 6:00 PM, Usage credits $1.92 of $20.00)
- Enterprise account popover (inline): only Context window (101.4k / 1M (10%)) + "See detailed breakdown" — no limits shown
- Enterprise Settings → usage limits (after clicking through): "Your usage limits · Enterprise" — $4,411.85 of $5,000.00 spent · 88% used · Resets Mon, Aug 31, 6:00 PM MDT
- Hover tooltip on the context ring (Enterprise): shows only "Context 103.7k / 1M (10%)" plus model/effort (Sonnet 5, Medium) — no usage-limit info here either

Start by reproducing the context-ring popover on an Enterprise seat, then compare it with Settings → Usage limits and inspect the `/api/oauth/usage` path mentioned in #84443. Done means the popover shows Enterprise spend, monthly limit, percentage used, and reset date inline without requiring navigation to Settings.

Written by the indexing model from the issue text.