fix: show all configured Mistral models and fix model selection priority (#1360) (#1418)

* fix(mistral): show all configured models in model picker (#1360)

* fix(mistral): use correct API model names and prepend selected model

* chore(mistral): fix comment and normalize model ids for consistency

* fix(mistral): remove retired models, fix descriptor ids, add multi-model test

* fix(mistral): preserve original delimiter and fix codestral descriptor id

* fix(mistral): revert codestral descriptor to match shared model registry

* fix(mistral): revert profile mutation; align with documented contract

persistActiveProviderProfileModel() is now a no-op that returns the
active profile. Runtime model selection is a session-level choice
handled by mainLoopModelOverride (set by onChangeAppState before this
helper is called); the profile's model list should only change via an
explicit provider edit, not as a side-effect of /model.

This addresses the Copilot and jatmn review threads that flagged the
prior prepend behavior:

  - contradicted the comment above the function stating session-level
    switching is owned by mainLoopModelOverride
  - caused unbounded list growth on rotation (A->B->C->D on a profile
    starting with A; B produced D; C; B; A; B)
  - used a separator inferred from a single-character substring of
    the model field that broke on mixed-separator inputs
  - the catalog also used inconsistent id naming

Catalog ids are normalized to the mistral-* scheme (mistral-devstral,
mistral-large, mistral-small, mistral-ministral-3b, mistral-codestral)
to match the existing prefix convention. apiName and modelDescriptorId
are unchanged so route metadata and descriptor lookups are unaffected.

New coverage:
  - providerProfiles.test.ts: locks the no-op contract for single- and
    multi-model profiles (semicolon and comma separators) and the
    in-list pick path that returns the active profile unchanged.

Resolves #1360

src/integrations/gateways/mistral.ts

@@ -49,6 +49,10 @@ export default defineGateway({
     models: [
       { id: 'mistral-vibe-cli', apiName: 'mistral-vibe-cli-latest', label: 'Vibe CLI Latest', modelDescriptorId: 'mistral-vibe-cli-latest' },
       { id: 'mistral-devstral', apiName: 'devstral-latest', label: 'Devstral Latest', modelDescriptorId: 'devstral-latest' },
+      { id: 'mistral-large', apiName: 'mistral-large-latest', label: 'Mistral Large Latest', modelDescriptorId: 'mistral-large-latest' },
+      { id: 'mistral-small', apiName: 'mistral-small-latest', label: 'Mistral Small Latest', modelDescriptorId: 'mistral-small-latest' },
+      { id: 'mistral-ministral-3b', apiName: 'ministral-3b-latest', label: 'Ministral 3B Latest', modelDescriptorId: 'ministral-3b-latest' },
+      { id: 'mistral-codestral', apiName: 'codestral-latest', label: 'Codestral Latest', modelDescriptorId: 'codestral' },
     ],
   },
   usage: { supported: false },

src/utils/providerProfiles.test.ts

@@ -1025,9 +1025,13 @@ describe('applyActiveProviderProfileFromConfig', () => {
 })
 
 describe('persistActiveProviderProfileModel', () => {
-  test('updates active profile model and current env for profile-managed sessions', async () => {
+  // The runtime active-model selection is owned by mainLoopModelOverride
+  // (set by onChangeAppState before this helper is called). This helper
+  // intentionally no longer mutates the profile's model list — see the
+  // docstring in providerProfiles.ts. Coverage below locks the no-op
+  // contract for both single- and multi-model profiles.
+  test('returns the active profile unchanged for a single-model profile', async () => {
     const {
-      applyProviderProfileToProcessEnv,
       getProviderProfiles,
       persistActiveProviderProfileModel,
     } = await importFreshProviderProfileModules()
@@ -1042,13 +1046,49 @@ describe('persistActiveProviderProfileModel', () => {
       providerProfiles: [activeProfile],
       activeProviderProfileId: activeProfile.id,
     }))
-    applyProviderProfileToProcessEnv(activeProfile)
 
     const updated = persistActiveProviderProfileModel('minimax-m2.5:cloud')
 
     expect(updated?.id).toBe(activeProfile.id)
-    expect(updated?.model).toBe('minimax-m2.5:cloud')
-    expect(process.env.OPENAI_MODEL).toBe('minimax-m2.5:cloud')
+    expect(updated?.model).toBe('kimi-k2.5:cloud')
+    const saved = getProviderProfiles().find(
+      (profile: ProviderProfile) => profile.id === activeProfile.id,
+    )
+    expect(saved?.model).toBe('kimi-k2.5:cloud')
+  })
+
+  test('does not mutate multi-model mistral profile when chosen model is out of list', async () => {
+    // Regression for #1360: the picker must never silently rewrite a
+    // provider's configured model list. The active model is a session-level
+    // choice handled by mainLoopModelOverride; the profile's model list
+    // only changes via an explicit provider edit. An earlier
+    // implementation prepended the chosen model to the list, which
+    // contradicted the documented contract and grew the list unboundedly
+    // on rotation.
+    const {
+      applyProviderProfileToProcessEnv,
+      getProviderProfiles,
+      persistActiveProviderProfileModel,
+    } = await importFreshProviderProfileModules()
+    const activeProfile = buildMistralProfile({
+      id: 'saved_mistral',
+      baseUrl: 'https://api.mistral.ai/v1',
+      model: 'devstral-latest; mistral-small-latest',
+    })
+
+    saveMockGlobalConfig(current => ({
+      ...current,
+      providerProfiles: [activeProfile],
+      activeProviderProfileId: activeProfile.id,
+    }))
+    applyProviderProfileToProcessEnv(activeProfile)
+
+    const updated = persistActiveProviderProfileModel('mistral-large-latest')
+
+    expect(updated?.id).toBe(activeProfile.id)
+    // The configured list is preserved verbatim regardless of the chosen
+    // model being in or out of the list.
+    expect(updated?.model).toBe('devstral-latest; mistral-small-latest')
     expect(process.env.CLAUDE_CODE_PROVIDER_PROFILE_ENV_APPLIED_ID).toBe(
       activeProfile.id,
     )
@@ -1056,17 +1096,20 @@ describe('persistActiveProviderProfileModel', () => {
     const saved = getProviderProfiles().find(
       (profile: ProviderProfile) => profile.id === activeProfile.id,
     )
-    expect(saved?.model).toBe('minimax-m2.5:cloud')
+    expect(saved?.model).toBe('devstral-latest; mistral-small-latest')
   })
 
-  test('does not mutate process env when session is not profile-managed', async () => {
+  test('preserves comma-separated multi-model list when chosen model is already a member', async () => {
+    // Switching between models already in the list is a session-level
+    // choice. The list itself must be preserved exactly as configured.
     const {
       getProviderProfiles,
       persistActiveProviderProfileModel,
     } = await importFreshProviderProfileModules()
-    const activeProfile = buildProfile({
-      id: 'saved_openai',
-      model: 'kimi-k2.5:cloud',
+    const activeProfile = buildMistralProfile({
+      id: 'saved_mistral',
+      baseUrl: 'https://api.mistral.ai/v1',
+      model: 'devstral-latest, mistral-small-latest, mistral-large-latest',
     })
 
     saveMockGlobalConfig(current => ({
@@ -1075,18 +1118,17 @@ describe('persistActiveProviderProfileModel', () => {
       activeProviderProfileId: activeProfile.id,
     }))
 
-    process.env.CLAUDE_CODE_USE_OPENAI = '1'
-    process.env.OPENAI_MODEL = 'cli-model'
-    delete process.env.CLAUDE_CODE_PROVIDER_PROFILE_ENV_APPLIED
-    delete process.env.CLAUDE_CODE_PROVIDER_PROFILE_ENV_APPLIED_ID
+    const updated = persistActiveProviderProfileModel('mistral-small-latest')
 
-    persistActiveProviderProfileModel('minimax-m2.5:cloud')
-
-    expect(process.env.OPENAI_MODEL).toBe('cli-model')
+    expect(updated?.model).toBe(
+      'devstral-latest, mistral-small-latest, mistral-large-latest',
+    )
     const saved = getProviderProfiles().find(
       (profile: ProviderProfile) => profile.id === activeProfile.id,
     )
-    expect(saved?.model).toBe('minimax-m2.5:cloud')
+    expect(saved?.model).toBe(
+      'devstral-latest, mistral-small-latest, mistral-large-latest',
+    )
   })
 })
 

src/utils/providerProfiles.ts

@@ -858,56 +858,20 @@ export function persistActiveProviderProfileModel(
     return null
   }
 
-  // If the model is already part of the profile's model list, don't
-  // overwrite the field. This preserves comma-separated model lists like
-  // "glm-4.5, glm-4.7". Switching between models in the list is a
-  // session-level choice handled by mainLoopModelOverride, not a profile
-  // edit — the profile's model list should only change via explicit edit.
-  const existingModels = parseModelList(activeProfile.model)
-  if (existingModels.includes(nextModel)) {
-    return activeProfile
-  }
-
-  saveGlobalConfig(current => {
-    const currentProfiles = getProviderProfiles(current)
-    const profileIndex = currentProfiles.findIndex(
-      profile => profile.id === activeProfile.id,
-    )
-
-    if (profileIndex < 0) {
-      return current
-    }
-
-    const currentProfile = currentProfiles[profileIndex]
-    if (currentProfile.model === nextModel) {
-      return current
-    }
-
-    const nextProfiles = [...currentProfiles]
-    nextProfiles[profileIndex] = {
-      ...currentProfile,
-      model: nextModel,
-    }
-
-    return {
-      ...current,
-      providerProfiles: nextProfiles,
-    }
-  })
-
-  const resolvedProfile = getActiveProviderProfile()
-  if (!resolvedProfile || resolvedProfile.id !== activeProfile.id) {
-    return null
-  }
-
-  if (
-    process.env[PROFILE_ENV_APPLIED_FLAG] === '1' &&
-    trimOrUndefined(process.env[PROFILE_ENV_APPLIED_ID]) === resolvedProfile.id
-  ) {
-    applyProviderProfileToProcessEnv(resolvedProfile)
-  }
-
-  return resolvedProfile
+  // Runtime model selection is a session-level choice handled by
+  // mainLoopModelOverride (see src/hooks/useMainLoopModel.ts), not a
+  // profile edit. Whether the chosen model is already part of the
+  // profile's list or not, do NOT mutate profile.model here:
+  //   - if it IS in the list, the list is already correct (no-op)
+  //   - if it ISN'T, the user picked an out-of-list model for the
+  //     session and the profile's list should only change via an
+  //     explicit provider edit, not by side-effect of /model.
+  // An earlier implementation prepended out-of-list models to the
+  // profile, which (a) contradicted this contract, (b) caused
+  // unbounded list growth on rotation, and (c) used a separator
+  // inferred from a single-character substring of the model field
+  // that broke on mixed-separator inputs.
+  return activeProfile
 }
 
 /**