feat(chat): allow custom model IDs

[zhoubeiqing]

Summary

• allow users to enter a custom model ID from the new-conversation model selector
• add a custom model action to the in-session /models dialog, including Enter-to-apply
• persist explicitly selected custom defaults so provider catalog refreshes do not reset them
• clear the custom marker when the user returns to a catalog model

Motivation

Provider adapters already pass model values through to their SDK/CLI integrations, but the UI only allowed selecting values present in the provider catalog. The catalog reconciliation logic also replaced any non-catalog value with the provider default.

This provides a manual fallback for custom Anthropic-compatible gateways and other providers that expose model IDs CloudCLI cannot discover. It addresses the selection limitation described in #910 and is complementary to #975: dynamically discovered models can still appear in the catalog, while unlisted models remain usable through explicit input.

Behavior

• exact catalog model IDs continue to use the existing selection flow
• a non-empty value that is not an exact catalog ID is offered as a custom model
• existing sessions apply the custom model on the next response
• new-session defaults survive reloads and model catalog refreshes

Validation

• npm run typecheck
• ESLint on the three changed files (0 errors; one existing Tailwind arbitrary-value warning in CommandResultModal.tsx)
• npm run build:client (successful; existing CSS minifier and bundle-size warnings remain)

Summary by CodeRabbit

• New Features
  • Added support for entering and selecting custom model IDs for each provider.
  • Model search now offers a “Use custom model ID” option when no matching model is found.
  • Custom model IDs can be selected by clicking the option or pressing Enter.
  • Custom selections are remembered and remain available even when not listed among current models.
  • Improved model selector prompts to clarify that users can search or enter a custom ID.

[coderabbitai]

📝 Walkthrough

Walkthrough

Custom model IDs can be entered and selected from provider model interfaces. Selections are passed through updated callbacks, persisted with per-provider markers, and retained during model reconciliation even when absent from current provider options.

Changes

Custom model selection

Layer / File(s)	Summary
Persist and reconcile custom models src/components/chat/hooks/useChatProviderState.ts	Provider state stores custom-model markers, preserves marked models outside current options, and accepts custom-selection options.
Add custom models to command modal src/components/chat/view/subcomponents/CommandResultModal.tsx	The modal supports custom model IDs through search, Enter-key selection, and a dedicated action.
Add custom models to empty-state selector src/components/chat/view/subcomponents/ProviderSelectionEmptyState.tsx	The selector controls model input, offers unmatched IDs as custom options, and persists custom selections.

Sequence Diagram(s)

sequenceDiagram
  participant ModelSelector
  participant useChatProviderState
  participant localStorage
  ModelSelector->>useChatProviderState: selectProviderModel(provider, model, custom option)
  useChatProviderState->>localStorage: store model and custom marker
  useChatProviderState->>localStorage: read custom marker during reconciliation
  useChatProviderState-->>ModelSelector: preserve selected custom model

Loading

Suggested reviewers: viper151

Poem

A rabbit typed a model ID,
Then hopped where custom choices hide.
The marker stayed, the model remained,
Though provider lists were rearranged.
“Enter,” I cheered, “and let it run!”
🐇✨ Custom models, carrots won!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title is concise and accurately summarizes the main change: adding support for custom model IDs in chat.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

🧹 Nitpick comments (1)

src/components/chat/hooks/useChatProviderState.ts (1)

140-146: 📐 Maintainability & Code Quality | 🔵 Trivial | ⚡ Quick win

Extract the custom-model marker persistence into a shared helper. The ${provider}-custom-model marker convention (write 'true' when custom, remove otherwise) is duplicated across two layers and read back by pickStoredOrCurrent. A single helper keeps the storage-key/value convention from silently diverging.

• src/components/chat/hooks/useChatProviderState.ts#L140-L146: replace the inline marker write/remove in setStoredProviderModel with the shared helper (e.g. setCustomModelMarker(targetProvider, isCustom)).
• src/components/chat/view/subcomponents/ProviderSelectionEmptyState.tsx#L158-L164: replace the inline marker write/remove in setModelForProvider with the same helper.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@src/components/chat/hooks/useChatProviderState.ts` around lines 140 - 146,
The custom-model marker persistence is duplicated across setStoredProviderModel
and setModelForProvider. Add a shared setCustomModelMarker helper that writes
'true' for custom models and removes the marker otherwise, then replace both
inline implementations in src/components/chat/hooks/useChatProviderState.ts
(lines 140-146) and
src/components/chat/view/subcomponents/ProviderSelectionEmptyState.tsx (lines
158-164) with calls to that helper.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Nitpick comments:
In `@src/components/chat/hooks/useChatProviderState.ts`:
- Around line 140-146: The custom-model marker persistence is duplicated across
setStoredProviderModel and setModelForProvider. Add a shared
setCustomModelMarker helper that writes 'true' for custom models and removes the
marker otherwise, then replace both inline implementations in
src/components/chat/hooks/useChatProviderState.ts (lines 140-146) and
src/components/chat/view/subcomponents/ProviderSelectionEmptyState.tsx (lines
158-164) with calls to that helper.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: 7a929ed4-af55-4eb5-a70c-a9c5e57a9578

📥 Commits

Reviewing files that changed from the base of the PR and between 5884573 and fa0980e.

📒 Files selected for processing (3)

• src/components/chat/hooks/useChatProviderState.ts
• src/components/chat/view/subcomponents/CommandResultModal.tsx
• src/components/chat/view/subcomponents/ProviderSelectionEmptyState.tsx