Feat/multi model provider support (#692)

* test: add tests for provider model env updates and multi-model profiles

Add comprehensive tests covering:
- OPENAI_MODEL/ANTHROPIC_MODEL env updates on provider activation
- Cross-provider type switches (openai ↔ anthropic) clearing stale env
- Multi-model profile activation using only the first model for env vars
- Model options cache population from comma-separated model lists
- getProfileModelOptions generating correct ModelOption arrays

* feat: multi-model provider support and model auto-switch

Support comma-separated model names in provider profiles (e.g.
"glm-4.7, glm-4.7-flash"). The first model is used as default on
activation; all models appear in the /model picker for easy switching.

When switching active providers, the session model now automatically
updates to the new provider's first model. The multi-model list is
preserved across switches and /model selections.

Changes:
- Add parseModelList, getPrimaryModel, hasMultipleModels utilities
  with full test coverage (19 tests)
- Use getPrimaryModel when applying profiles to process.env so only
  the primary model is set in OPENAI_MODEL/ANTHROPIC_MODEL
- Update ProviderManager UI to hint at multi-model syntax and show
  model count in provider list summaries
- Populate model options cache from multi-model profiles on activation
  so all models appear in /model picker regardless of base URL type
- Guard persistActiveProviderProfileModel against overwriting
  comma-separated lists: models already in the profile are session
  selections, not profile edits
- Set AppState.mainLoopModel to the actual model string on provider
  switch so Anthropic profiles use the configured model instead of
  falling back to the built-in default

* fix: only show profile models when provider profile env is applied

Guard the profile model picker options behind a
PROFILE_ENV_APPLIED check. getActiveProviderProfile() has a
?? profiles[0] fallback that returns the first profile even when
no profile is explicitly active, causing users with inactive
profiles to lose all standard model options (Opus, Haiku, etc.)
from the /model picker.

* fix: show all model names for profiles with 3 or fewer models

Instead of a summary format for multi-model profiles, display all
model names when there are 3 or fewer. Only use the "+ N more"
format for profiles with 4+ models.

* fix: preserve standard model options in picker alongside profile models

The previous implementation used an early return that replaced all
standard picker options (Opus, Haiku, Sonnet for Anthropic; Codex/GPT
models for OpenAI) with only the profile's custom models.

Changes:
- Collect profile models into a shared array instead of early returning
- Append profile models to firstParty path (Opus + Haiku + Sonnet + custom)
- Append profile models to PAYG 3P path (Codex + Sonnet + Opus + Haiku + custom)
- Guard collection behind PROFILE_ENV_APPLIED to avoid ?? profiles[0] fallback

Fixes review feedback: standard models are no longer hidden when a
provider profile with custom models is active. Users see both the
standard options and their profile's models.

---------

Co-authored-by: Ali Alakbarli <ali.alakbarli@users.noreply.github.com>

src/utils/model/modelOptions.ts

@@ -33,7 +33,11 @@ import {
 } from './model.js'
 import { has1mContext } from '../context.js'
 import { getGlobalConfig } from '../config.js'
-import { getActiveOpenAIModelOptionsCache } from '../providerProfiles.js'
+import {
+  getActiveOpenAIModelOptionsCache,
+  getActiveProviderProfile,
+  getProfileModelOptions,
+} from '../providerProfiles.js'
 import { getCachedOllamaModelOptions, isOllamaProvider } from './ollamaModels.js'
 import { getCachedNvidiaNimModelOptions, isNvidiaNimProvider } from './nvidiaNimModels.js'
 import { getCachedMiniMaxModelOptions, isMiniMaxProvider } from './minimaxModels.js'
@@ -476,6 +480,20 @@ function getModelOptionsBase(fastMode = false): ModelOption[] {
     ]
   }
 
+  // When a provider profile's env is applied, collect its models so they
+  // can be appended to the standard picker options below.
+  // We check PROFILE_ENV_APPLIED to avoid the ?? profiles[0] fallback in
+  // getActiveProviderProfile which would affect users with inactive profiles.
+  const profileEnvApplied = process.env.CLAUDE_CODE_PROVIDER_PROFILE_ENV_APPLIED === '1'
+  const profileModelOptions: ModelOption[] = []
+  if (profileEnvApplied) {
+    const activeProfile = getActiveProviderProfile()
+    if (activeProfile) {
+      const models = getProfileModelOptions(activeProfile)
+      profileModelOptions.push(...models)
+    }
+  }
+
   // PAYG 1P API: Default (Sonnet) + Sonnet 1M + Opus 4.6 + Opus 1M + Haiku
   if (getAPIProvider() === 'firstParty') {
     const payg1POptions = [getDefaultOptionForUser(fastMode)]
@@ -491,6 +509,7 @@ function getModelOptionsBase(fastMode = false): ModelOption[] {
       }
     }
     payg1POptions.push(getHaiku45Option())
+    payg1POptions.push(...profileModelOptions)
     return payg1POptions
   }
 
@@ -530,6 +549,7 @@ function getModelOptionsBase(fastMode = false): ModelOption[] {
   } else {
     payg3pOptions.push(getHaikuOption())
   }
+  payg3pOptions.push(...profileModelOptions)
   return payg3pOptions
 }