feat: Add error handling and type inference for f2a library

- Introduced a new error handling module (`errors.rs`) with custom error types for various failure scenarios.
- Implemented a type inference function (`infer_column_type`) in `types.rs` to determine semantic column types based on Polars data types and statistics.
- Created a comprehensive end-to-end test suite (`test_e2e.py`) to validate the functionality of the f2a library across multiple data formats and analysis configurations.
- Added unit tests for core functionalities, including import checks, version validation, and analysis configuration presets.
- Enhanced report generation tests to ensure HTML output and internationalization support.
- Established pytest fixtures for reusable test data across multiple test cases.

Author: CocoRoF

.github/workflows/ci.yml

@@ -0,0 +1,120 @@
+# ──────────────────────────────────────────────────────────────
+#  f2a CI — Lint, build, test on every push / PR
+#
+#  IMPORTANT:
+#    - Uses pip exclusively. Do NOT add uv/astral-sh actions.
+#    - maturin builds from source on each platform (no pre-built wheels).
+# ──────────────────────────────────────────────────────────────
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+env:
+  PIP_DISABLE_PIP_VERSION_CHECK: "1"
+  PYTHONDONTWRITEBYTECODE: "1"
+
+jobs:
+  # ── Rust check & clippy ───────────────────────────────────
+  rust-check:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@stable
+        with:
+          components: clippy, rustfmt
+
+      - name: Cache cargo
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/bin
+            ~/.cargo/registry/index
+            ~/.cargo/registry/cache
+            ~/.cargo/git/db
+            target
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+          restore-keys: ${{ runner.os }}-cargo-
+
+      - name: cargo fmt --check
+        run: cargo fmt --all -- --check
+
+      - name: cargo clippy
+        run: cargo clippy --all-targets -- -D warnings
+
+      - name: cargo test
+        run: cargo test --release
+
+  # ── Python test matrix ────────────────────────────────────
+  test:
+    needs: rust-check
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-14]
+        python-version: ["3.10", "3.11", "3.12", "3.13"]
+        exclude:
+          # Cross-platform spot-check: full Python matrix on Linux only,
+          # 3.12 on Windows/macOS to save CI minutes.
+          - os: windows-latest
+            python-version: "3.10"
+          - os: windows-latest
+            python-version: "3.11"
+          - os: windows-latest
+            python-version: "3.13"
+          - os: macos-14
+            python-version: "3.10"
+          - os: macos-14
+            python-version: "3.11"
+          - os: macos-14
+            python-version: "3.13"
+
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@stable
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+
+      - name: Cache cargo
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.cargo/bin
+            ~/.cargo/registry/index
+            ~/.cargo/registry/cache
+            ~/.cargo/git/db
+            target
+          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+          restore-keys: ${{ runner.os }}-cargo-
+
+      - name: Build extension (maturin develop)
+        shell: bash
+        run: |
+          python -m pip install --upgrade pip maturin
+          maturin develop --release
+
+      - name: Install test dependencies
+        shell: bash
+        run: |
+          python -m pip install pytest pandas numpy matplotlib seaborn scipy pyarrow rich jinja2
+
+      - name: Run tests
+        run: python -m pytest tests/ -v --tb=short