* fix(omo): use lowercase keys for builtin agent definitions
OMO config schema expects all agent keys to be lowercase.
Updated OMO_BUILTIN_AGENTS keys (Sisyphus → sisyphus, Hephaestus →
hephaestus, etc.) and aligned Rust test fixtures accordingly.
* feat(omo): add i18n support and tooltips for agent/category descriptions
* feat(omo): add preset model variants for thinking level support
Add OPENCODE_PRESET_MODEL_VARIANTS constant with variant definitions
for Google, OpenAI, and Anthropic models. The omoModelVariantsMap
builder now falls back to presets when config-defined variants are
absent, enabling the variant selector for supported models.
* feat(omo): replace model select with searchable combobox and improve fallback handling
* feat(omo): enrich preset model defaults and metadata fallback
* fix(omo): preserve custom fields and align otherFields import/validation
* fix: resolve omo clippy warnings and include app update
