fix(cli): preserve installer fallback chains in generated config (#3144)

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/cli/model-fallback.ts

@@ -2,11 +2,13 @@ import {
   CLI_AGENT_MODEL_REQUIREMENTS,
   CLI_CATEGORY_MODEL_REQUIREMENTS,
 } from "./model-fallback-requirements"
+import type { FallbackModelObject } from "../config/schema/fallback-models"
+import type { FallbackEntry } from "../shared/model-requirements"
 import type { InstallConfig } from "./types"
 
 import type { AgentConfig, CategoryConfig, GeneratedOmoConfig } from "./model-fallback-types"
 import { applyOpenAiOnlyModelCatalog, isOpenAiOnlyAvailability } from "./openai-only-model-catalog"
-import { toProviderAvailability } from "./provider-availability"
+import { isProviderAvailable, toProviderAvailability } from "./provider-availability"
 import {
 	getSisyphusFallbackChain,
 	isAnyFallbackEntryAvailable,
@@ -14,6 +16,7 @@ import {
 	isRequiredProviderAvailable,
 	resolveModelFromChain,
 } from "./fallback-chain-resolution"
+import { transformModelForProvider } from "./provider-model-id-transform"
 
 export type { GeneratedOmoConfig } from "./model-fallback-types"
 
@@ -22,6 +25,44 @@ const ZAI_MODEL = "zai-coding-plan/glm-4.7"
 const ULTIMATE_FALLBACK = "opencode/gpt-5-nano"
 const SCHEMA_URL = "https://raw.githubusercontent.com/code-yeongyu/oh-my-openagent/dev/assets/oh-my-opencode.schema.json"
 
+function toFallbackModelObject(entry: FallbackEntry, provider: string): FallbackModelObject {
+  return {
+    model: `${provider}/${transformModelForProvider(provider, entry.model)}`,
+    ...(entry.variant ? { variant: entry.variant } : {}),
+    ...(entry.reasoningEffort ? { reasoningEffort: entry.reasoningEffort as FallbackModelObject["reasoningEffort"] } : {}),
+    ...(entry.temperature !== undefined ? { temperature: entry.temperature } : {}),
+    ...(entry.top_p !== undefined ? { top_p: entry.top_p } : {}),
+    ...(entry.maxTokens !== undefined ? { maxTokens: entry.maxTokens } : {}),
+    ...(entry.thinking ? { thinking: entry.thinking } : {}),
+  }
+}
+
+function attachFallbackModels<T extends AgentConfig | CategoryConfig>(
+  config: T,
+  fallbackChain: FallbackEntry[],
+  availability: ReturnType<typeof toProviderAvailability>,
+): T {
+  const expandedFallbacks = fallbackChain.flatMap((entry) =>
+    entry.providers
+      .filter((provider) => isProviderAvailable(provider, availability))
+      .map((provider) => toFallbackModelObject(entry, provider))
+  )
+  const primaryIndex = expandedFallbacks.findIndex((entry) => entry.model === config.model)
+  if (primaryIndex === -1) {
+    return config
+  }
+
+  const fallbackModels = expandedFallbacks.slice(primaryIndex + 1)
+  if (fallbackModels.length === 0) {
+    return config
+  }
+
+  return {
+    ...config,
+    fallback_models: fallbackModels,
+  }
+}
+
 
 
 export function generateModelConfig(config: InstallConfig): GeneratedOmoConfig {
@@ -85,7 +126,8 @@ export function generateModelConfig(config: InstallConfig): GeneratedOmoConfig {
       const resolved = resolveModelFromChain(fallbackChain, avail)
       if (resolved) {
         const variant = resolved.variant ?? req.variant
-        agents[role] = variant ? { model: resolved.model, variant } : { model: resolved.model }
+        const agentConfig = variant ? { model: resolved.model, variant } : { model: resolved.model }
+        agents[role] = attachFallbackModels(agentConfig, fallbackChain, avail)
       }
       continue
     }
@@ -100,7 +142,8 @@ export function generateModelConfig(config: InstallConfig): GeneratedOmoConfig {
     const resolved = resolveModelFromChain(req.fallbackChain, avail)
     if (resolved) {
       const variant = resolved.variant ?? req.variant
-      agents[role] = variant ? { model: resolved.model, variant } : { model: resolved.model }
+      const agentConfig = variant ? { model: resolved.model, variant } : { model: resolved.model }
+      agents[role] = attachFallbackModels(agentConfig, req.fallbackChain, avail)
     } else {
       agents[role] = { model: ULTIMATE_FALLBACK }
     }
@@ -123,7 +166,8 @@ export function generateModelConfig(config: InstallConfig): GeneratedOmoConfig {
     const resolved = resolveModelFromChain(fallbackChain, avail)
     if (resolved) {
       const variant = resolved.variant ?? req.variant
-      categories[cat] = variant ? { model: resolved.model, variant } : { model: resolved.model }
+      const categoryConfig = variant ? { model: resolved.model, variant } : { model: resolved.model }
+      categories[cat] = attachFallbackModels(categoryConfig, fallbackChain, avail)
     } else {
       categories[cat] = { model: ULTIMATE_FALLBACK }
     }