## What happened

The agents panel Codex tab toggles between the real Session/Weekly meters and an empty state.
When empty, the record carries:

```json
{"limits": [], "tierLabel": "", "usageStatusText": "Codex limits unavailable", "authHelpText": "account/read"}
```

`authHelpText` is `str(TimeoutError("account/read"))` — the `account/read` RPC to the Codex
app-server timed out. The ChatGPT login itself is fine throughout (`codex login status` →
"Logged in using ChatGPT"); minutes later the same call succeeds and meters reappear.

## Repro

Six sequential runs of the exact sequence `fetch_codex_rpc()` performs
(`codex -s read-only -a on-request app-server`, `initialize`, `account/read` with 4 s timeout):

```
run0: FAIL account/read after 4.16s
run1: FAIL account/read after 4.15s
run2: OK init=0.14s account=0.50s limits=0.68s
run3: OK init=0.13s account=0.47s limits=0.56s
run4: OK init=0.12s account=0.53s limits=1.09s
run5: FAIL account/read after 4.32s
```

3/6 time out. Latency is bimodal: ~0.5 s normally, past 4 s on the slow path (same auth,
same machine, seconds apart).

## Why the panel blanks instead of riding it out

Two compounding behaviors in the stock collectors:

1. `omarchy-agent-usage-codex::fetch_codex_rpc()` uses `timeout=4` for `account/read` with no
   retry, and on any exception returns `limits: []` — but `main()` still exits 0 printing
   valid JSON.
2. `omarchy-agent-usage-update::collect()` only keeps the old record when the collector exits
   nonzero or prints invalid JSON. A valid-JSON-but-empty record overwrites last-good meters,
   so one slow RPC blanks the tab until the next successful run (up to ~900 s).

## Expected

Transient app-server slowness should not blank the meters: retry `account/read` (backoff and/or
a longer timeout — the slow path exceeds 4 s while the fast path is ~0.5 s), and if it still
fails, exit nonzero / print nothing so the updater keeps the last-good record. That is already
the contract the `opencode-go` adapter follows (`exit 1` = no data, engine keeps previous
limits).

## Environment

- `omarchy version`: 4.0.4-1
- `codex --version`: codex-cli 0.156.1
- ChatGPT Plus plan (two rate-limit windows)
- Full `omarchy debug` log available on request.