🪲 BUG-#32: Custom model silently reverted to defaultModel on every provider

[FernandoCelmer]

Description

• src/features/settings/settings.controller.ts — storedModelFor() and healStaleModel() no longer treat "not in def.models" as stale. def.models is a curated shortlist for the QuickPick menu, not an exhaustive whitelist — local providers (Ollama, LM Studio) in particular have open-ended model names. healStaleModel() now only falls back to defaultModel when the active provider has no model set at all, instead of force-resetting any custom entry.

Motivation and Context

Setting a custom model via "Custom…" in the model picker didn't stick — postSettings() (called right after updateSetting("model", model) in both changeProviderModel() and connectProvider(), and again on nearly every settings-affecting action) ran healStaleModel(), which force-reverted the model back to defaultModel whenever it wasn't a member of the hardcoded models: string[] list. Reported against Ollama, but reproduces for every entry in PROVIDER_CATALOG.

Closes #32.

Types of changes

• Bug fix (change that fixes an issue)
• New feature
• Documentation

Checklist

• I have performed a self-review of my own code
• I have added tests that prove my fix is effective
• I have updated the CHANGELOG
• I have updated the documentation accordingly

[FernandoCelmer]

Two blocking issues found in the model validation logic.