feat(KB-330): rename internal packages from @kb/* to @fusion/*

- Rename @kb/core, @kb/dashboard, @kb/engine to @fusion/* namespace
- Update all import statements across 143+ files to use new package names
- Update workspace dependencies and root package.json references
- Fix bundler configurations (tsup, vite) for new package names
- Update test files and fix typecheck issues
- Add changeset file documenting the package rename

packages/dashboard/app/utils/modelPresets.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import type { ModelPreset } from "@kb/core";
+import type { ModelPreset } from "@fusion/core";
 import {
   applyPresetToSelection,
   generatePresetId,

packages/dashboard/app/utils/modelPresets.ts

@@ -1,4 +1,4 @@
-import type { ModelPreset } from "@kb/core";
+import type { ModelPreset } from "@fusion/core";
 
 export function getPresetByName(presets: ModelPreset[], name: string): ModelPreset | undefined {
   const normalizedName = name.trim().toLowerCase();

packages/dashboard/app/utils/worktreeGrouping.test.ts

@@ -1,6 +1,6 @@
 import { describe, it, expect } from "vitest";
 import { groupByWorktree, getWorktreeLabel } from "./worktreeGrouping";
-import type { Task } from "@kb/core";
+import type { Task } from "@fusion/core";
 
 function makeTask(overrides: Partial<Task> & { id: string }): Task {
   return {

packages/dashboard/app/utils/worktreeGrouping.ts

@@ -1,4 +1,4 @@
-import type { Task } from "@kb/core";
+import type { Task } from "@fusion/core";
 
 export interface WorktreeGroupData {
   label: string;
@@ -18,8 +18,8 @@ export function getWorktreeLabel(worktreePath: string): string {
 
 /**
  * Topological sort of tasks by dependency order.
- * Mirrors resolveDependencyOrder from @kb/core but inlined to avoid
- * build alias issues (Vite aliases @kb/core to types.ts only).
+ * Mirrors resolveDependencyOrder from @fusion/core but inlined to avoid
+ * build alias issues (Vite aliases @fusion/core to types.ts only).
  */
 function resolveDependencyOrder(tasks: Task[]): string[] {
   const taskMap = new Map(tasks.map((t) => [t.id, t]));