fix: model catalog fallback for not_configured status

[Marnie0415]

Summary

Two fixes for model whitelist injection failure on Codex App 26.623+:

1. Rust backend (model_catalog.rs): When settings.json exists but the active relay profile has no models, fall through to read from config.toml instead of returning not_configured immediately.

2. Inject script (renderer-inject.js): When /codex-model-catalog returns not_configured, add a fallback that reads modelList from the active relay profile via /settings/get.

Problem

On Codex App 26.623+:

• app-server-manager-signals- module is not found, breaking one layer of whitelist injection
• /codex-model-catalog returns {"status":"not_configured"} even when settings.json has a populated modelList in the active relay profile
• This happens because read_codex_model_catalog() returns early from the relay profile path without checking config.toml when models are empty

Root Cause

In read_codex_model_catalog() (model_catalog.rs), when settings.json exists, the function always returns from the relay profile path. If relay_profile_model_ids() returns empty (e.g. modelList parsing issue), it returns not_configured without ever falling through to read model_catalog_json from config.toml.

Fix Details

Rust (model_catalog.rs)

• Check if relay profile models are non-empty before returning
• If empty, continue to read_codex_model_catalog_from_home() which reads config.toml

JS (renderer-inject.js)

• In loadCodexModelCatalog(), when bridge returns not_configured with empty models
• Fetch settings via /settings/get with 3s timeout
• Parse modelList from active relay profile
• Populate codexModelCatalog.models
• Diagnostic events for fallback success/failure

Testing

• Non-breaking: fallback only triggers when original path returns empty models
• Verified: relay profile modelList format is newline/comma separated

Related

• Closes Model whitelist injection fails: app-server-manager-signals- module not found in Codex 26.623+ #1324