feat(categories): add disable field to CategoryConfigSchema

Allow individual categories to be disabled via `disable: true` in
config. Introduce shared `mergeCategories()` utility to centralize
category merging and disabled filtering across all 7 consumption sites.

src/tools/delegate-task/categories.ts

@@ -32,7 +32,10 @@ export function resolveCategoryConfig(
   const userConfig = userCategories?.[categoryName]
   const hasExplicitUserConfig = userConfig !== undefined
 
-  // Check if category requires a specific model - bypass if user explicitly provides config
+  if (userConfig?.disable) {
+    return null
+  }
+
   const categoryReq = CATEGORY_MODEL_REQUIREMENTS[categoryName]
   if (categoryReq?.requiresModel && availableModels && !hasExplicitUserConfig) {
     if (!isModelAvailable(categoryReq.requiresModel, availableModels)) {

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

@@ -1,7 +1,7 @@
 import type { ModelFallbackInfo } from "../../features/task-toast-manager/types"
 import type { DelegateTaskArgs } from "./types"
 import type { ExecutorContext } from "./executor-types"
-import { DEFAULT_CATEGORIES } from "./constants"
+import { mergeCategories } from "../../shared/merge-categories"
 import { SISYPHUS_JUNIOR_AGENT } from "./sisyphus-junior-agent"
 import { resolveCategoryConfig } from "./categories"
 import { parseModelString } from "./model-string-parser"
@@ -30,7 +30,8 @@ export async function resolveCategoryExecution(
   const availableModels = await getAvailableModelsForDelegateTask(client)
 
   const categoryName = args.category!
-  const categoryExists = DEFAULT_CATEGORIES[categoryName] !== undefined || userCategories?.[categoryName] !== undefined
+  const enabledCategories = mergeCategories(userCategories)
+  const categoryExists = enabledCategories[categoryName] !== undefined
 
   const resolved = resolveCategoryConfig(categoryName, {
     userCategories,
@@ -41,7 +42,7 @@ export async function resolveCategoryExecution(
 
   if (!resolved) {
     const requirement = CATEGORY_MODEL_REQUIREMENTS[categoryName]
-    const allCategoryNames = Object.keys({ ...DEFAULT_CATEGORIES, ...userCategories }).join(", ")
+    const allCategoryNames = Object.keys(enabledCategories).join(", ")
 
     if (categoryExists && requirement?.requiresModel) {
       return {
@@ -146,7 +147,7 @@ Available categories: ${allCategoryNames}`,
   const categoryPromptAppend = resolved.promptAppend || undefined
 
   if (!categoryModel && !actualModel) {
-    const categoryNames = Object.keys({ ...DEFAULT_CATEGORIES, ...userCategories })
+    const categoryNames = Object.keys(enabledCategories)
     return {
       agentToUse: "",
       categoryModel: undefined,

src/tools/delegate-task/tools.ts

@@ -1,6 +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 { CATEGORY_DESCRIPTIONS } from "./constants"
+import { mergeCategories } from "../../shared/merge-categories"
 import { log } from "../../shared/logger"
 import { buildSystemContent } from "./prompt-builder"
 import type {
@@ -26,7 +27,7 @@ export { buildSystemContent } from "./prompt-builder"
 export function createDelegateTask(options: DelegateTaskToolOptions): ToolDefinition {
   const { userCategories } = options
 
-  const allCategories = { ...DEFAULT_CATEGORIES, ...userCategories }
+  const allCategories = mergeCategories(userCategories)
   const categoryNames = Object.keys(allCategories)
   const categoryExamples = categoryNames.map(k => `'${k}'`).join(", ")