Merge pull request #2594 from MoerAI/fix/subagent-fallback-model-v2

fix(agent-registration): always attempt fallback when model resolution fails (fixes #2427, supersedes #2517)

src/agents/builtin-agents/general-agents.ts

@@ -8,6 +8,7 @@ import { buildAgent, isFactory } from "../agent-builder"
 import { applyOverrides } from "./agent-overrides"
 import { applyEnvironmentContext } from "./environment-context"
 import { applyModelResolution, getFirstFallbackModel } from "./model-resolution"
+import { log } from "../../shared/logger"
 
 export function collectPendingBuiltinAgents(input: {
   agentSources: Record<BuiltinAgentName, import("../agent-builder").AgentSource>
@@ -75,7 +76,13 @@ export function collectPendingBuiltinAgents(input: {
       availableModels,
       systemDefaultModel,
     })
-    if (!resolution && isFirstRunNoCache && !override?.model) {
+    if (!resolution) {
+      if (override?.model) {
+        log("[agent-registration] User-configured model could not be resolved, falling back", {
+          agent: agentName,
+          configuredModel: override.model,
+        })
+      }
       resolution = getFirstFallbackModel(requirement)
     }
     if (!resolution) continue