feat(projman): add /test-gen command for test generation

Adds test generation command that complements existing /test-check:
- Auto-detects test framework (pytest, jest, vitest, go test, etc.)
- Generates unit, integration, e2e, or snapshot tests
- Creates happy path, edge case, and error tests
- Supports multiple languages (Python, JavaScript, Go, etc.)
- Integrates with /test-check for generate-then-verify workflow

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

plugins/projman/commands/test-gen.md

@@ -0,0 +1,118 @@
+---
+description: Generate tests for specified code - creates unit, integration, or e2e tests
+---
+
+# Test Generation
+
+Generate comprehensive tests for specified code.
+
+## Usage
+```
+/test-gen <target> [--type=<type>] [--framework=<framework>]
+```
+
+**Target:** File path, function name, class name, or module
+**Type:** unit (default), integration, e2e, snapshot
+**Framework:** Auto-detected or specify (pytest, jest, vitest, go test, etc.)
+
+## Process
+
+1. **Analyze Target Code**
+   - Parse function/class signatures
+   - Identify dependencies and side effects
+   - Map input types and return types
+   - Find edge cases from logic branches
+
+2. **Determine Test Strategy**
+
+   | Code Pattern | Test Approach |
+   |--------------|---------------|
+   | Pure function | Unit tests with varied inputs |
+   | Class with state | Setup/teardown, state transitions |
+   | External calls | Mocks/stubs for dependencies |
+   | Database ops | Integration tests with fixtures |
+   | API endpoints | Request/response tests |
+   | UI components | Snapshot + interaction tests |
+
+3. **Generate Tests**
+
+   For each target function/method:
+   - Happy path test (expected inputs → expected output)
+   - Edge cases (empty, null, boundary values)
+   - Error cases (invalid inputs → expected errors)
+   - Type variations (if dynamic typing)
+
+4. **Test Structure**
+   ```python
+   # Example output for Python/pytest
+
+   import pytest
+   from module import target_function
+
+   class TestTargetFunction:
+       """Tests for target_function."""
+
+       def test_happy_path(self):
+           """Standard input produces expected output."""
+           result = target_function(valid_input)
+           assert result == expected_output
+
+       def test_empty_input(self):
+           """Empty input handled gracefully."""
+           result = target_function("")
+           assert result == default_value
+
+       def test_invalid_input_raises(self):
+           """Invalid input raises ValueError."""
+           with pytest.raises(ValueError):
+               target_function(invalid_input)
+
+       @pytest.mark.parametrize("input,expected", [
+           (case1_in, case1_out),
+           (case2_in, case2_out),
+       ])
+       def test_variations(self, input, expected):
+           """Multiple input variations."""
+           assert target_function(input) == expected
+   ```
+
+5. **Output**
+```
+## Tests Generated
+
+### Target: src/orders.py:calculate_total
+
+### File Created: tests/test_orders.py
+
+### Tests (6 total)
+- test_calculate_total_happy_path
+- test_calculate_total_empty_items
+- test_calculate_total_negative_price_raises
+- test_calculate_total_with_discount
+- test_calculate_total_with_tax
+- test_calculate_total_parametrized_cases
+
+### Coverage Estimate
+- Line coverage: ~85%
+- Branch coverage: ~70%
+
+### Run Tests
+pytest tests/test_orders.py -v
+```
+
+## Framework Detection
+
+| Files Present | Framework Used |
+|---------------|----------------|
+| pytest.ini, conftest.py | pytest |
+| jest.config.* | jest |
+| vitest.config.* | vitest |
+| *_test.go | go test |
+| Cargo.toml | cargo test |
+| mix.exs | ExUnit |
+
+## Integration with /test-check
+
+- `/test-gen` creates new tests
+- `/test-check` verifies tests pass
+- Typical flow: `/test-gen src/new_module.py` → `/test-check`