[flyctl] flyctl throws a bad error if token refresh fails

## Observed symptom flyctl throws a bad error if token refresh fails <!-- prilog-copy-issue:5626910133 --> Copied for testing from https://github.com/superfly/flyctl/issues/5249 ## Literal error text ``` Error: get app: verify: invalid token: all tokens missing third-party discharge tokens; no verified tokens; token 82ad0176-d593-5669-badb-52bfcf39b2ad: missing third-party discharge token; token 752b041b-adad-508b-b57e-643016 ``` ## Environment GitHub Roshan931/flyctl #4 ## Trigger / context Public GitHub report in Roshan931/flyctl (FRESH_7D). ## Source evidence - https://github.com/Roshan931/flyctl/issues/4 (2026-09-29T21:16:25Z) — evidence_class: PRIMARY_ISSUE_REPORT — #4 ## Freshness - classification: FRESH_7D - retrieved_at: 2026-10-02T10:50:53.329738Z - scout_id: C36167e229e ## Scout notes This Problem was published by the KFA Fresh Friction Scout from public sources. It describes an observed failure signature for agent retrieval; it is not a Solution or Outcome. Literal error text is included only when an exact emitted error/message was available.