Add Taskfile for unified dev workflow across all components (#6080)

## Add Taskfile for unified dev workflow

### Summary
- Introduces [Taskfile](https://taskfile.dev/) as the single CLI entry
point for all development workflows across backend, frontend, engine,
Docker, and desktop
- ~80 tasks organized into 6 namespaces: `backend:`, `frontend:`,
`engine:`, `docker:`, `desktop:`, plus root-level composites
- All CI workflows migrated to use Task
- Deletes `engine/Makefile` and `scripts/build-tauri-jlink.{sh,bat}` —
replaced by Task equivalents
- Removes redundant npm scripts (`dev`, `build`, `prep`, `lint`, `test`,
`typecheck:all`) from `package.json`
- Smart dependency caching: `sources`/`status`/`generates`
fingerprinting, CI-aware `npm ci` vs `npm install`, `run: once` for
parallel dep deduplication

### What this does NOT do
- Does not replace Gradle, npm, or Docker — Taskfile is a thin
orchestration wrapper
- Does not change application code or behavior

### Install
```
npm install -g @go-task/cli    # or: brew install go-task, winget install Task.Task
```

### Quick start
```
task --list       # discover all tasks
task install      # install all deps
task dev          # start backend + frontend
task dev:all      # also start AI engine
task test         # run all tests
task check        # quick quality gate (local dev)
task check:all    # full CI quality gate
```

### Test plan
- [ ] Install `task` CLI and run `task --list` — verify all tasks
display
- [ ] Run `task install` — verify frontend + engine deps install
- [ ] Run `task dev` — verify backend + frontend start, Ctrl+C exits
cleanly
- [ ] Run `task frontend:check` — verify typecheck + lint + test pass
- [ ] Run `task desktop:dev` — verify jlink builds are cached on second
run
- [ ] Verify CI passes on all workflows

---------

Co-authored-by: James Brunton <[email protected]>

.github/workflows/tauri-build.yml

@@ -128,86 +128,16 @@ jobs:
         with:
           gradle-version: 9.3.1
 
-      - name: Build Java backend with JLink
-        working-directory: ./
-        shell: bash
-        run: |
-          chmod +x ./gradlew
-          echo "🔧 Building Stirling-PDF JAR..."
-          # STIRLING_PDF_DESKTOP_UI=false ./gradlew bootJar --no-daemon
-          ./gradlew build -x spotlessApply -x spotlessCheck -x test -x sonarqube
-
-          # Find the built JAR
-          STIRLING_JAR=$(ls app/core/build/libs/stirling-pdf-*.jar | head -n 1)
-          echo "✅ Built JAR: $STIRLING_JAR"
-
-          # Create Tauri directories
-          mkdir -p ./frontend/src-tauri/libs
-          mkdir -p ./frontend/src-tauri/runtime
-
-          # Copy JAR to Tauri libs
-          cp "$STIRLING_JAR" ./frontend/src-tauri/libs/
-          echo "✅ JAR copied to Tauri libs"
-
-          # Analyze JAR dependencies for jlink modules
-          echo "🔍 Analyzing JAR dependencies..."
-          if command -v jdeps &> /dev/null; then
-            DETECTED_MODULES=$(jdeps --print-module-deps --ignore-missing-deps "$STIRLING_JAR" 2>/dev/null || echo "")
-            if [ -n "$DETECTED_MODULES" ]; then
-              echo "📋 jdeps detected modules: $DETECTED_MODULES"
-              MODULES="$DETECTED_MODULES,java.compiler,java.instrument,java.management,java.naming,java.net.http,java.prefs,java.rmi,java.scripting,java.security.jgss,java.security.sasl,java.sql,java.transaction.xa,java.xml.crypto,jdk.crypto.ec,jdk.crypto.cryptoki,jdk.unsupported"
-            else
-              echo "⚠️ jdeps analysis failed, using predefined modules"
-              MODULES="java.base,java.compiler,java.desktop,java.instrument,java.logging,java.management,java.naming,java.net.http,java.prefs,java.rmi,java.scripting,java.security.jgss,java.security.sasl,java.sql,java.transaction.xa,java.xml,java.xml.crypto,jdk.crypto.ec,jdk.crypto.cryptoki,jdk.unsupported"
-            fi
-          else
-            echo "⚠️ jdeps not available, using predefined modules"
-            MODULES="java.base,java.compiler,java.desktop,java.instrument,java.logging,java.management,java.naming,java.net.http,java.prefs,java.rmi,java.scripting,java.security.jgss,java.security.sasl,java.sql,java.transaction.xa,java.xml,java.xml.crypto,jdk.crypto.ec,jdk.crypto.cryptoki,jdk.unsupported"
-          fi
-
-          # Create custom JRE with jlink (always rebuild)
-          echo "🔧 Creating custom JRE with jlink..."
-          echo "📋 Using modules: $MODULES"
-
-          # Remove any existing JRE
-          rm -rf ./frontend/src-tauri/runtime/jre
-
-          # Create the custom JRE
-          jlink \
-            --add-modules "$MODULES" \
-            --strip-debug \
-            --compress=2 \
-            --no-header-files \
-            --no-man-pages \
-            --output ./frontend/src-tauri/runtime/jre
-
-          if [ ! -d "./frontend/src-tauri/runtime/jre" ]; then
-            echo "❌ Failed to create JLink runtime"
-            exit 1
-          fi
-
-          # Test the bundled runtime
-          if [ -f "./frontend/src-tauri/runtime/jre/bin/java" ]; then
-            RUNTIME_VERSION=$(./frontend/src-tauri/runtime/jre/bin/java --version 2>&1 | head -n 1)
-            echo "✅ Custom JRE created successfully: $RUNTIME_VERSION"
-          else
-            echo "❌ Custom JRE executable not found"
-            exit 1
-          fi
-
-          # Calculate runtime size
-          RUNTIME_SIZE=$(du -sh ./frontend/src-tauri/runtime/jre | cut -f1)
-          echo "📊 Custom JRE size: $RUNTIME_SIZE"
+      - name: Setup Task
+        uses: go-task/setup-task@3be4020d41929789a01026e0e427a4321ce0ad44 # v2.0.0
+      - name: Prepare desktop build
+        run: task desktop:prepare
         env:
           MAVEN_USER: ${{ secrets.MAVEN_USER }}
           MAVEN_PASSWORD: ${{ secrets.MAVEN_PASSWORD }}
           MAVEN_PUBLIC_URL: ${{ secrets.MAVEN_PUBLIC_URL }}
           DISABLE_ADDITIONAL_FEATURES: true
 
-      - name: Install frontend dependencies
-        working-directory: ./frontend
-        run: npm ci
-
       # DigiCert KeyLocker Setup (Cloud HSM)
       - name: Setup DigiCert KeyLocker
         id: digicert-setup