refactor: modularize TUI, improve error handling, add CI caching and tests

Split monolithic app.go into focused modules (dashboard, chat, workflow,
config, agents, terminal, commands, handlers). Add proper error handling
for installer commands, proxy pipes, and MCP config parsing. Fix daemon
channel buffer, cap orchestrator history, compile think regex once, and
set HTTP timeouts on preview server. Improve CI with Go module caching,
dependency download step, and test stage with race detection.

😘 Generated with Crush

Assisted-by: GLM-5-Turbo via Crush <crush@charm.land>

.gitea/workflows/ci.yml

@@ -21,17 +21,37 @@ jobs:
           export PATH=/usr/local/go/bin:$PATH
           go version
 
-      - name: Build
+      - name: Cache Go modules
+        uses: actions/cache@v4
+        with:
+          path: |
+            /root/go/pkg/mod
+            /home/runner/go/pkg/mod
+          key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-go-
+
+      - name: Download dependencies
         run: |
           export PATH=/usr/local/go/bin:$PATH
-          go build -o muyue ./cmd/muyue/
-          ./muyue version
+          go mod download
 
       - name: Vet
         run: |
           export PATH=/usr/local/go/bin:$PATH
           go vet ./...
 
+      - name: Test
+        run: |
+          export PATH=/usr/local/go/bin:$PATH
+          go test ./... -v -race -timeout 60s
+
+      - name: Build
+        run: |
+          export PATH=/usr/local/go/bin:$PATH
+          go build -o muyue ./cmd/muyue/
+          ./muyue version
+
       - name: Build all platforms
         if: github.event_name == 'push'
         run: |