feat: CI/CD, Bash-Completion und README-Verbesserungen

- GitHub Actions CI Pipeline (Tests, Clippy, Format-Checks)
- GitHub Actions Release Pipeline (Multi-Platform Builds)
- Bash-Completion Script für Shell-Autovervollständigung
- Zsh-Completion Script (_ntu)
- README Badges (CI, Release, Version, License)
- Installationsanleitung für Pre-built Binaries
- Alte build.yaml entfernt (ersetzt durch moderne ci.yml)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -0,0 +1,107 @@
+name: CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+          - stable
+          - beta
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install Rust
+        uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: ${{ matrix.rust }}
+
+      - name: Cache cargo registry
+        uses: actions/cache@v4
+        with:
+          path: ~/.cargo/registry
+          key: ${{ runner.os }}-cargo-registry-${{ hashFiles('**/Cargo.lock') }}
+
+      - name: Cache cargo index
+        uses: actions/cache@v4
+        with:
+          path: ~/.cargo/git
+          key: ${{ runner.os }}-cargo-index-${{ hashFiles('**/Cargo.lock') }}
+
+      - name: Cache cargo build
+        uses: actions/cache@v4
+        with:
+          path: target
+          key: ${{ runner.os }}-cargo-build-target-${{ hashFiles('**/Cargo.lock') }}
+
+      - name: Run tests
+        run: cargo test --verbose
+
+      - name: Run tests (release mode)
+        run: cargo test --release --verbose
+
+  fmt:
+    name: Rustfmt
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install Rust
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          components: rustfmt
+
+      - name: Check formatting
+        run: cargo fmt --all -- --check
+
+  clippy:
+    name: Clippy
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install Rust
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          components: clippy
+
+      - name: Run clippy
+        run: cargo clippy --all-targets --all-features -- -D warnings
+
+  build:
+    name: Build
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+        include:
+          - os: ubuntu-latest
+            target: x86_64-unknown-linux-gnu
+          - os: macos-latest
+            target: x86_64-apple-darwin
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install Rust
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          target: ${{ matrix.target }}
+
+      - name: Build
+        run: cargo build --release --target ${{ matrix.target }}
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: ntu-${{ matrix.target }}
+          path: target/${{ matrix.target }}/release/ntu