feat: pivot to AI-native task management platform (#232)

Replace the agent framework codebase with a new monorepo structure
for an AI-native Linear-like product where agents are first-class citizens.

New architecture:
- server/ — Go backend (Chi + gorilla/websocket + sqlc)
  - API server with REST routes for issues, agents, inbox, workspaces
  - WebSocket hub for real-time updates
  - Local daemon entry point for agent runtime connection
  - PostgreSQL migration with 13 tables (issue, agent, inbox, etc.)
  - WebSocket protocol types for server<->daemon communication
- apps/web/ — Next.js 16 frontend
  - Dashboard layout with sidebar navigation
  - Route skeleton: inbox, issues, agents, board, settings
- packages/ui/ — Preserved shadcn/ui design system (26+ components)
- packages/types/ — Full API contract types (Issue, Agent, Workspace, Inbox, Events)
- packages/sdk/ — REST ApiClient + WebSocket WSClient
- packages/store/ — Zustand stores (issue, agent, inbox, auth)
- packages/hooks/ — React hooks (useIssues, useAgents, useInbox, useRealtime)
- packages/utils/ — Shared utilities

Removed: apps/cli, apps/desktop, apps/mobile, apps/gateway,
packages/core, skills/, and all agent-framework code.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -11,28 +11,7 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
-  lint:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v6
-
-      - name: Setup pnpm
-        uses: pnpm/action-setup@v4
-
-      - name: Setup Node.js
-        uses: actions/setup-node@v6
-        with:
-          node-version: 22
-          cache: pnpm
-
-      - name: Install dependencies
-        run: pnpm install
-
-      - name: Lint
-        run: pnpm --filter @multica/web --filter @multica/desktop lint
-
-  build-and-typecheck:
+  frontend:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
@@ -61,3 +40,21 @@ jobs:
 
       - name: Build, type check, and test
         run: pnpm turbo build typecheck test
+
+  backend:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: "1.24"
+          cache-dependency-path: server/go.sum
+
+      - name: Build
+        run: cd server && go build ./...
+
+      - name: Test
+        run: cd server && go test ./...