feat(KB-502): implement dashboard multi-project UX

- Add project selector, health badge, and overview components to dashboard
- Add multi-project API functions (api.ts) for cross-project operations
- Update App.tsx with project context and navigation improvements
- Add script-store.ts for centralized project script management
- Extend types with multi-project support: SetupState, MigrationOptions, etc.
- Add project runtime fields: baseCommitSha, modifiedFiles, missionId, sliceId
- Add setupComplete to global settings for first-run wizard tracking
- Add project-level settings: scripts, setupScript, ntfyDashboardHost
- Add backward-compatible addSteeringComment method to TaskStore

packages/dashboard/app/components/Header.tsx

@@ -1,6 +1,6 @@
 import { useState, useEffect, useRef, useCallback } from "react";
 import { Settings, Pause, Play, Square, LayoutGrid, List, Terminal, Lightbulb, Search, X, Activity, MoreHorizontal, Clock, Folder, History, GitBranch, Workflow, Bot, ChevronLeft } from "lucide-react";
-import type { ProjectInfo } from "@fusion/core";
+import type { ProjectInfo } from "../api";
 import { ProjectSelector } from "./ProjectSelector";
 import { QuickScriptsDropdown } from "./QuickScriptsDropdown";