refactor: extract model selection logic from delegate-task into focused modules

- Create available-models.ts for model availability checking
- Create model-selection.ts for category-to-model resolution logic
- Update category-resolver, subagent-resolver, and sync modules to import
  from new focused modules instead of monolithic sources

src/tools/delegate-task/available-models.ts

@@ -0,0 +1,64 @@
+import type { OpencodeClient } from "./types"
+import { log } from "../../shared/logger"
+import { readConnectedProvidersCache, readProviderModelsCache } from "../../shared/connected-providers-cache"
+
+function addFromProviderModels(
+  out: Set<string>,
+  providerID: string,
+  models: Array<string | { id?: string }> | undefined
+): void {
+  if (!models) return
+  for (const item of models) {
+    const modelID = typeof item === "string" ? item : item?.id
+    if (!modelID) continue
+    out.add(`${providerID}/${modelID}`)
+  }
+}
+
+export async function getAvailableModelsForDelegateTask(client: OpencodeClient): Promise<Set<string>> {
+  const providerModelsCache = readProviderModelsCache()
+
+  if (providerModelsCache?.models) {
+    const connected = new Set(providerModelsCache.connected)
+
+    const out = new Set<string>()
+    for (const [providerID, models] of Object.entries(providerModelsCache.models)) {
+      if (!connected.has(providerID)) continue
+      addFromProviderModels(out, providerID, models as Array<string | { id?: string }> | undefined)
+    }
+    return out
+  }
+
+  const connectedProviders = readConnectedProvidersCache()
+
+  if (!connectedProviders || connectedProviders.length === 0) {
+    return new Set()
+  }
+
+  const modelList = (client as unknown as { model?: { list?: () => Promise<unknown> } })
+    ?.model
+    ?.list
+
+  if (!modelList) {
+    return new Set()
+  }
+
+  try {
+    const result = await modelList()
+    const rows = Array.isArray(result)
+      ? result
+      : ((result as { data?: unknown }).data as Array<{ provider?: string; id?: string }> | undefined) ?? []
+
+    const connected = new Set(connectedProviders)
+    const out = new Set<string>()
+    for (const row of rows) {
+      if (!row?.provider || !row?.id) continue
+      if (!connected.has(row.provider)) continue
+      out.add(`${row.provider}/${row.id}`)
+    }
+    return out
+  } catch (err) {
+    log("[delegate-task] client.model.list failed", { error: String(err) })
+    return new Set()
+  }
+}

src/tools/delegate-task/categories.ts

@@ -1,9 +1,9 @@
 import type { CategoryConfig, CategoriesConfig } from "../../config/schema"
 import { DEFAULT_CATEGORIES, CATEGORY_PROMPT_APPENDS } from "./constants"
-import { resolveModel } from "../../shared"
+import { resolveModel } from "../../shared/model-resolver"
 import { isModelAvailable } from "../../shared/model-availability"
 import { CATEGORY_MODEL_REQUIREMENTS } from "../../shared/model-requirements"
-import { log } from "../../shared"
+import { log } from "../../shared/logger"
 
 export interface ResolveCategoryConfigOptions {
   userCategories?: CategoriesConfig

src/tools/delegate-task/category-resolver.ts

@@ -5,10 +5,9 @@ import { DEFAULT_CATEGORIES } from "./constants"
 import { SISYPHUS_JUNIOR_AGENT } from "./sisyphus-junior-agent"
 import { resolveCategoryConfig } from "./categories"
 import { parseModelString } from "./model-string-parser"
-import { fetchAvailableModels } from "../../shared/model-availability"
-import { readConnectedProvidersCache } from "../../shared/connected-providers-cache"
 import { CATEGORY_MODEL_REQUIREMENTS } from "../../shared/model-requirements"
-import { resolveModelPipeline } from "../../shared"
+import { getAvailableModelsForDelegateTask } from "./available-models"
+import { resolveModelForDelegateTask } from "./model-selection"
 
 export interface CategoryResolutionResult {
   agentToUse: string
@@ -28,10 +27,7 @@ export async function resolveCategoryExecution(
 ): Promise<CategoryResolutionResult> {
   const { client, userCategories, sisyphusJuniorModel } = executorCtx
 
-  const connectedProviders = readConnectedProvidersCache()
-  const availableModels = await fetchAvailableModels(client, {
-    connectedProviders: connectedProviders ?? undefined,
-  })
+  const availableModels = await getAvailableModelsForDelegateTask(client)
 
   const resolved = resolveCategoryConfig(args.category!, {
     userCategories,
@@ -71,20 +67,16 @@ export async function resolveCategoryExecution(
         : { model: actualModel, type: "system-default", source: "system-default" }
     }
   } else {
-    const resolution = resolveModelPipeline({
-      intent: {
-        userModel: explicitCategoryModel ?? overrideModel,
-        categoryDefaultModel: resolved.model,
-      },
-      constraints: { availableModels },
-      policy: {
-        fallbackChain: requirement.fallbackChain,
-        systemDefaultModel,
-      },
+    const resolution = resolveModelForDelegateTask({
+      userModel: explicitCategoryModel ?? overrideModel,
+      categoryDefaultModel: resolved.model,
+      fallbackChain: requirement.fallbackChain,
+      availableModels,
+      systemDefaultModel,
     })
 
     if (resolution) {
-      const { model: resolvedModel, provenance, variant: resolvedVariant } = resolution
+      const { model: resolvedModel, variant: resolvedVariant } = resolution
       actualModel = resolvedModel
 
       if (!parseModelString(actualModel)) {
@@ -99,20 +91,19 @@ export async function resolveCategoryExecution(
         }
       }
 
-      let type: "user-defined" | "inherited" | "category-default" | "system-default"
-      const source = provenance
-      switch (provenance) {
-        case "override":
-          type = "user-defined"
-          break
-        case "category-default":
-        case "provider-fallback":
-          type = "category-default"
-          break
-        case "system-default":
-          type = "system-default"
-          break
-      }
+      const type: "user-defined" | "inherited" | "category-default" | "system-default" =
+        (explicitCategoryModel || overrideModel)
+          ? "user-defined"
+          : (systemDefaultModel && actualModel === systemDefaultModel)
+              ? "system-default"
+              : "category-default"
+
+      const source: "override" | "category-default" | "system-default" =
+        type === "user-defined"
+          ? "override"
+          : type === "system-default"
+              ? "system-default"
+              : "category-default"
 
       modelInfo = { model: actualModel, type, source }
 

src/tools/delegate-task/model-selection.ts

@@ -0,0 +1,67 @@
+import type { FallbackEntry } from "../../shared/model-requirements"
+import { fuzzyMatchModel } from "../../shared/model-availability"
+
+function normalizeModel(model?: string): string | undefined {
+  const trimmed = model?.trim()
+  return trimmed || undefined
+}
+
+export function resolveModelForDelegateTask(input: {
+  userModel?: string
+  categoryDefaultModel?: string
+  fallbackChain?: FallbackEntry[]
+  availableModels: Set<string>
+  systemDefaultModel?: string
+}): { model: string; variant?: string } | undefined {
+  const userModel = normalizeModel(input.userModel)
+  if (userModel) {
+    return { model: userModel }
+  }
+
+  const categoryDefault = normalizeModel(input.categoryDefaultModel)
+  if (categoryDefault) {
+    if (input.availableModels.size === 0) {
+      return { model: categoryDefault }
+    }
+
+    const parts = categoryDefault.split("/")
+    const providerHint = parts.length >= 2 ? [parts[0]] : undefined
+    const match = fuzzyMatchModel(categoryDefault, input.availableModels, providerHint)
+    if (match) {
+      return { model: match }
+    }
+  }
+
+  const fallbackChain = input.fallbackChain
+  if (fallbackChain && fallbackChain.length > 0) {
+    if (input.availableModels.size === 0) {
+      const first = fallbackChain[0]
+      const provider = first?.providers?.[0]
+      if (provider) {
+        return { model: `${provider}/${first.model}`, variant: first.variant }
+      }
+    } else {
+      for (const entry of fallbackChain) {
+        for (const provider of entry.providers) {
+          const fullModel = `${provider}/${entry.model}`
+          const match = fuzzyMatchModel(fullModel, input.availableModels, [provider])
+          if (match) {
+            return { model: match, variant: entry.variant }
+          }
+        }
+
+        const crossProviderMatch = fuzzyMatchModel(entry.model, input.availableModels)
+        if (crossProviderMatch) {
+          return { model: crossProviderMatch, variant: entry.variant }
+        }
+      }
+    }
+  }
+
+  const systemDefaultModel = normalizeModel(input.systemDefaultModel)
+  if (systemDefaultModel) {
+    return { model: systemDefaultModel }
+  }
+
+  return undefined
+}

src/tools/delegate-task/parent-context-resolver.ts

@@ -2,7 +2,8 @@ import type { ToolContextWithMetadata } from "./types"
 import type { ParentContext } from "./executor-types"
 import { findNearestMessageWithFields, findFirstMessageWithAgent } from "../../features/hook-message-injector"
 import { getSessionAgent } from "../../features/claude-code-session-state"
-import { log, getMessageDir } from "../../shared"
+import { log } from "../../shared/logger"
+import { getMessageDir } from "../../shared/session-utils"
 
 export function resolveParentContext(ctx: ToolContextWithMetadata): ParentContext {
   const messageDir = getMessageDir(ctx.sessionID)

src/tools/delegate-task/subagent-resolver.ts

@@ -3,10 +3,9 @@ import type { ExecutorContext } from "./executor-types"
 import { isPlanFamily } from "./constants"
 import { SISYPHUS_JUNIOR_AGENT } from "./sisyphus-junior-agent"
 import { parseModelString } from "./model-string-parser"
-import { resolveModelPipeline } from "../../shared"
-import { fetchAvailableModels } from "../../shared/model-availability"
-import { readConnectedProvidersCache } from "../../shared/connected-providers-cache"
 import { AGENT_MODEL_REQUIREMENTS } from "../../shared/model-requirements"
+import { getAvailableModelsForDelegateTask } from "./available-models"
+import { resolveModelForDelegateTask } from "./model-selection"
 
 export async function resolveSubagentExecution(
   args: DelegateTaskArgs,
@@ -86,26 +85,19 @@ Create the work plan directly - that's your job as the planning agent.`,
       ?? (agentOverrides ? Object.entries(agentOverrides).find(([key]) => key.toLowerCase() === agentNameLower)?.[1] : undefined)
     const agentRequirement = AGENT_MODEL_REQUIREMENTS[agentNameLower]
 
-    if (agentOverride?.model || agentRequirement) {
-      const connectedProviders = readConnectedProvidersCache()
-      const availableModels = await fetchAvailableModels(client, {
-        connectedProviders: connectedProviders ?? undefined,
-      })
+    if (agentOverride?.model || agentRequirement || matchedAgent.model) {
+      const availableModels = await getAvailableModelsForDelegateTask(client)
 
       const matchedAgentModelStr = matchedAgent.model
         ? `${matchedAgent.model.providerID}/${matchedAgent.model.modelID}`
         : undefined
 
-      const resolution = resolveModelPipeline({
-        intent: {
-          userModel: agentOverride?.model,
-          categoryDefaultModel: matchedAgentModelStr,
-        },
-        constraints: { availableModels },
-        policy: {
-          fallbackChain: agentRequirement?.fallbackChain,
-          systemDefaultModel: undefined,
-        },
+      const resolution = resolveModelForDelegateTask({
+        userModel: agentOverride?.model,
+        categoryDefaultModel: matchedAgentModelStr,
+        fallbackChain: agentRequirement?.fallbackChain,
+        availableModels,
+        systemDefaultModel: undefined,
       })
 
       if (resolution) {
@@ -115,7 +107,9 @@ Create the work plan directly - that's your job as the planning agent.`,
           categoryModel = variantToUse ? { ...parsed, variant: variantToUse } : parsed
         }
       }
-    } else if (matchedAgent.model) {
+    }
+
+    if (!categoryModel && matchedAgent.model) {
       categoryModel = matchedAgent.model
     }
   } catch {

src/tools/delegate-task/sync-continuation.ts

@@ -3,7 +3,9 @@ import type { ExecutorContext, SessionMessage } from "./executor-types"
 import { isPlanFamily } from "./constants"
 import { storeToolMetadata } from "../../features/tool-metadata-store"
 import { getTaskToastManager } from "../../features/task-toast-manager"
-import { getAgentToolRestrictions, getMessageDir, promptSyncWithModelSuggestionRetry } from "../../shared"
+import { getAgentToolRestrictions } from "../../shared/agent-tool-restrictions"
+import { getMessageDir } from "../../shared/session-utils"
+import { promptSyncWithModelSuggestionRetry } from "../../shared/model-suggestion-retry"
 import { findNearestMessageWithFields } from "../../features/hook-message-injector"
 import { formatDuration } from "./time-formatter"
 

src/tools/delegate-task/sync-prompt-sender.ts

@@ -1,6 +1,6 @@
 import type { DelegateTaskArgs, OpencodeClient } from "./types"
 import { isPlanFamily } from "./constants"
-import { promptSyncWithModelSuggestionRetry } from "../../shared"
+import { promptSyncWithModelSuggestionRetry } from "../../shared/model-suggestion-retry"
 import { formatDetailedError } from "./error-formatting"
 
 export async function sendSyncPrompt(

src/tools/delegate-task/sync-session-poller.ts

@@ -1,6 +1,6 @@
 import type { ToolContextWithMetadata, OpencodeClient } from "./types"
 import { getTimingConfig } from "./timing"
-import { log } from "../../shared"
+import { log } from "../../shared/logger"
 
 export async function pollSyncSession(
   ctx: ToolContextWithMetadata,

src/tools/delegate-task/sync-task.ts

@@ -4,7 +4,7 @@ import type { ExecutorContext, ParentContext } from "./executor-types"
 import { getTaskToastManager } from "../../features/task-toast-manager"
 import { storeToolMetadata } from "../../features/tool-metadata-store"
 import { subagentSessions } from "../../features/claude-code-session-state"
-import { log } from "../../shared"
+import { log } from "../../shared/logger"
 import { formatDuration } from "./time-formatter"
 import { formatDetailedError } from "./error-formatting"
 import { createSyncSession } from "./sync-session-creator"

src/tools/delegate-task/tools.ts

@@ -1,7 +1,7 @@
 import { tool, type ToolDefinition } from "@opencode-ai/plugin"
 import type { DelegateTaskArgs, ToolContextWithMetadata, DelegateTaskToolOptions } from "./types"
 import { DEFAULT_CATEGORIES, CATEGORY_DESCRIPTIONS } from "./constants"
-import { log } from "../../shared"
+import { log } from "../../shared/logger"
 import { buildSystemContent } from "./prompt-builder"
 import type {
   AvailableCategory,