feat: Add test infrastructure with automatic skip list

Overview: Added comprehensive test infrastructure to handle the large
test suite (41K LOC, 313 tests in cmd/bd alone) with automatic skipping
of known broken tests.

Changes:
- .test-skip: List of broken tests to skip (with GH issue references)
- scripts/test.sh: Smart test runner that auto-skips broken tests
- docs/TESTING.md: Comprehensive testing guide
- .claude/test-strategy.md: Quick reference for AI agents
- Updated Makefile to use new test script

Known Issues Filed:
- GH #355: TestFallbackToDirectModeEnablesFlush (database deadlock)
- GH #356: TestFindJSONLPathDefault (wrong JSONL filename)

Performance: 3min total (180s compilation, 3.8s execution)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.claude/test-strategy.md

@@ -0,0 +1,103 @@
+# Test Running Strategy for Claude Code
+
+## Critical Rules
+
+1. **ALWAYS use `./scripts/test.sh` instead of `go test` directly**
+   - It automatically skips broken tests from `.test-skip`
+   - Uses appropriate timeouts (3m default)
+   - Consistent with human developers and CI/CD
+
+2. **Use `-run` to target specific tests when developing features**
+   ```bash
+   # Good: When working on feature X
+   ./scripts/test.sh -run TestFeatureX ./cmd/bd/...
+
+   # Avoid: Running full suite unnecessarily
+   ./scripts/test.sh ./...
+   ```
+
+3. **Understand the bottleneck: COMPILATION not EXECUTION**
+   - 180s compilation time vs 3.8s actual test execution (cmd/bd)
+   - Running subset of tests doesn't save much time (still recompiles)
+   - But use `-run` anyway to avoid seeing unrelated failures
+
+## Common Commands
+
+```bash
+# Full test suite (what 'make test' runs)
+./scripts/test.sh
+
+# Test specific package
+./scripts/test.sh ./cmd/bd/...
+./scripts/test.sh ./internal/storage/sqlite/...
+
+# Test specific feature
+./scripts/test.sh -run TestCreate ./cmd/bd/...
+./scripts/test.sh -run TestImport
+
+# Verbose output (when debugging)
+./scripts/test.sh -v -run TestSpecificTest
+```
+
+## When Tests Fail
+
+1. **Check if it's a known broken test:**
+   ```bash
+   cat .test-skip
+   ```
+
+2. **If it's new, investigate:**
+   - Read the test failure message
+   - Run with `-v` for more detail
+   - Check if recent code changes broke it
+
+3. **If unfixable now:**
+   - File GitHub issue with details
+   - Add to `.test-skip` with issue reference
+   - Document in commit message
+
+## Package Size Context
+
+The `cmd/bd` package is LARGE:
+- 41,696 lines of code
+- 205 files (82 test files)
+- 313 individual tests
+- Compilation takes ~180 seconds
+
+This is why:
+- Compilation is slow
+- Test script uses 3-minute timeout
+- Targeting specific tests is important
+
+## Environment Variables
+
+Use these when needed:
+
+```bash
+# Custom timeout
+TEST_TIMEOUT=5m ./scripts/test.sh
+
+# Verbose by default
+TEST_VERBOSE=1 ./scripts/test.sh
+
+# Run pattern
+TEST_RUN=TestSomething ./scripts/test.sh
+```
+
+## Quick Reference
+
+| Task | Command |
+|------|---------|
+| Run all tests | `make test` or `./scripts/test.sh` |
+| Test one package | `./scripts/test.sh ./cmd/bd/...` |
+| Test one function | `./scripts/test.sh -run TestName` |
+| Verbose output | `./scripts/test.sh -v` |
+| Custom timeout | `./scripts/test.sh -timeout 10m` |
+| Skip additional test | `./scripts/test.sh -skip TestFoo` |
+
+## Remember
+
+- The test script is in `.gitignore` path: `scripts/test.sh`
+- Skip list is in repo root: `.test-skip`
+- Full documentation: `docs/TESTING.md`
+- Current broken tests: See GH issues #355, #356