refactor: revamp ultrabrain category with deep work mindset

- Add variant: max to ultrabrain's gemini-3-pro fallback entry
- Rename STRATEGIC_CATEGORY_PROMPT_APPEND to ULTRABRAIN_CATEGORY_PROMPT_APPEND
- Keep original strategic advisor prompt content (no micromanagement instructions)
- Update description: use only for genuinely hard tasks, give clear goals only
- Update tests to match renamed constant

src/tools/delegate-task/constants.ts

@@ -14,8 +14,8 @@ Design-first mindset:
 AVOID: Generic fonts, purple gradients on white, predictable layouts, cookie-cutter patterns.
 </Category_Context>`
 
-export const STRATEGIC_CATEGORY_PROMPT_APPEND = `<Category_Context>
-You are working on BUSINESS LOGIC / ARCHITECTURE tasks.
+export const ULTRABRAIN_CATEGORY_PROMPT_APPEND = `<Category_Context>
+You are working on DEEP LOGICAL REASONING / COMPLEX ARCHITECTURE tasks.
 
 Strategic advisor mindset:
 - Bias toward simplicity: least complex solution that fulfills requirements
@@ -167,7 +167,7 @@ export const DEFAULT_CATEGORIES: Record<string, CategoryConfig> = {
 
 export const CATEGORY_PROMPT_APPENDS: Record<string, string> = {
   "visual-engineering": VISUAL_CATEGORY_PROMPT_APPEND,
-  ultrabrain: STRATEGIC_CATEGORY_PROMPT_APPEND,
+  ultrabrain: ULTRABRAIN_CATEGORY_PROMPT_APPEND,
   artistry: ARTISTRY_CATEGORY_PROMPT_APPEND,
   quick: QUICK_CATEGORY_PROMPT_APPEND,
   "unspecified-low": UNSPECIFIED_LOW_CATEGORY_PROMPT_APPEND,
@@ -177,7 +177,7 @@ export const CATEGORY_PROMPT_APPENDS: Record<string, string> = {
 
 export const CATEGORY_DESCRIPTIONS: Record<string, string> = {
   "visual-engineering": "Frontend, UI/UX, design, styling, animation",
-  ultrabrain: "Deep logical reasoning, complex architecture decisions requiring extensive analysis",
+  ultrabrain: "Use ONLY for genuinely hard, logic-heavy tasks. Give clear goals only, not step-by-step instructions.",
   artistry: "Highly creative/artistic tasks, novel ideas",
   quick: "Trivial tasks - single file changes, typo fixes, simple modifications",
   "unspecified-low": "Tasks that don't fit other categories, low effort required",

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

@@ -63,12 +63,12 @@ describe("sisyphus-task", () => {
       expect(promptAppend).toContain("Design-first")
     })
 
-    test("ultrabrain category has strategic prompt", () => {
+    test("ultrabrain category has deep logical reasoning prompt", () => {
       // #given
       const promptAppend = CATEGORY_PROMPT_APPENDS["ultrabrain"]
 
       // #when / #then
-      expect(promptAppend).toContain("BUSINESS LOGIC")
+      expect(promptAppend).toContain("DEEP LOGICAL REASONING")
       expect(promptAppend).toContain("Strategic advisor")
     })
   })

src/tools/delegate-task/tools.ts

@@ -541,7 +541,8 @@ To continue this session: session_id="${args.session_id}"`
            }
           } else {
           const resolution = resolveModelWithFallback({
-              userModel: userCategories?.[args.category]?.model ?? resolved.model ?? sisyphusJuniorModel,
+              userModel: userCategories?.[args.category]?.model,
+              categoryDefaultModel: resolved.model ?? sisyphusJuniorModel,
               fallbackChain: requirement.fallbackChain,
               availableModels,
               systemDefaultModel,
@@ -555,18 +556,19 @@ To continue this session: session_id="${args.session_id}"`
                return `Invalid model format "${actualModel}". Expected "provider/model" format (e.g., "anthropic/claude-sonnet-4-5").`
              }
 
-             let type: "user-defined" | "inherited" | "category-default" | "system-default"
-             switch (source) {
-                case "override":
-                  type = "user-defined"
-                  break
-                case "provider-fallback":
-                  type = "category-default"
-                  break
-                case "system-default":
-                  type = "system-default"
-                  break
-             }
+              let type: "user-defined" | "inherited" | "category-default" | "system-default"
+              switch (source) {
+                 case "override":
+                   type = "user-defined"
+                   break
+                 case "category-default":
+                 case "provider-fallback":
+                   type = "category-default"
+                   break
+                 case "system-default":
+                   type = "system-default"
+                   break
+              }
 
              modelInfo = { model: actualModel, type, source }