fix(desktop): stop PUT /api/config storing its own transport envelope

[agentforce314]

A real ~/.clawcodex/config.json had a full stale snapshot nested under a config key, with the live stt (voice transcription) block stranded inside it — so the backend, which reads the top level, never saw the configured voice settings.

{
  default_provider, providers, session, settings, env, projects, logoColor,
  config: {            ← envelope stored as data
    default_provider, providers, session, settings, projects, logoColor,
    stt: { enabled: true, provider: "openai", ... }   ← stranded here
  }
}

The nested block was identifiable as a redacted GET /api/config response (providers carrying only base_url/default_model, no env), and stale — its openai provider still pointed at the endpoint the user had since changed.

Why it stuck

saveClawCodexConfig sends {"config": {...}}, and the settings panel autosaves the whole record it last read. So one mis-nested write is copied forward on every later save, and _deep_merge only ever adds — nothing could ever remove it. Worse, the envelope shadows real settings: anything written inside it is invisible to a backend that reads the top level.

config is not a key in the config schema, so its presence can only ever be an envelope stored by mistake.

Fix

• Unwrap repeatedly on the way in. A double wrap is the shape that does the damage: unwrapping once leaves a config key behind, which then merges in as data.
• Drop the envelope when saving, so a config that already picked one up is repaired by its next ordinary write — no migration step.
• Strip it on the way out, so a stored envelope can't be round-tripped straight back by the renderer's whole-record autosave.

Credentials still survive the redacted round trip — that is what the deep-merge is for, and there is a test asserting an api_key is not lost.

Testing

New tests/server/test_desktop_config_envelope.py: single and double unwrap, bare records untouched, a wrapped save landing at the top level with credentials intact, and an existing envelope repaired by the next save. Full Python suite: 9912 passed, 15 skipped.

🤖 Generated with Claude Code