test: add bats test suite for lib/ helper scripts

110 tests across 10 test files covering all lib/ scripts:
- archeflow-event.sh: JSONL format, seq numbering, parent fields, validation
- archeflow-memory.sh: add/list/decay/forget/inject/extract commands
- archeflow-git.sh: branch creation, commit format, merge strategies, safety
- archeflow-report.sh: markdown output, summary mode, in-progress handling
- archeflow-progress.sh: progress.md generation, JSON mode, error handling
- archeflow-score.sh: archetype scoring, effectiveness report, validation
- archeflow-dag.sh: DAG rendering, color flags, tree structure
- archeflow-rollback.sh: arg parsing, phase validation, mutual exclusivity
- archeflow-init.sh: template listing, clone from project, arg validation
- archeflow-review.sh: diff modes, stats, branch/commit range review

Includes test_helper.bash (shared setup/teardown with temp git repos)
and scripts/run-tests.sh runner.

tests/archeflow-review.bats

@@ -0,0 +1,82 @@
+# Tests for archeflow-review.sh — git diff extraction for code review.
+#
+# Validates: argument parsing, diff modes, stats output, empty diff handling.
+
+setup() {
+  load test_helper
+  _common_setup
+}
+
+teardown() {
+  _common_teardown
+}
+
+@test "review: --help shows usage" {
+  run "$LIB_DIR/archeflow-review.sh" --help
+  [ "$status" -eq 0 ]
+  [[ "$output" == *"Usage"* ]]
+  [[ "$output" == *"--branch"* ]]
+  [[ "$output" == *"--commit"* ]]
+}
+
+@test "review: exits 1 when no changes to review" {
+  run "$LIB_DIR/archeflow-review.sh"
+  [ "$status" -eq 1 ]
+  [[ "$output" == *"No changes"* ]]
+}
+
+@test "review: shows diff for uncommitted changes" {
+  echo "new content" > testfile.txt
+  git add testfile.txt
+  run "$LIB_DIR/archeflow-review.sh"
+  [ "$status" -eq 0 ]
+  [[ "$output" == *"testfile.txt"* ]]
+}
+
+@test "review: --stat-only prints stats without diff content" {
+  echo "stat content" > statfile.txt
+  git add statfile.txt
+  run "$LIB_DIR/archeflow-review.sh" --stat-only
+  [ "$status" -eq 0 ]
+  # stderr has stats, stdout should be empty (no diff)
+  # But run captures both, so just check it ran ok
+  [[ "$output" == *"Review Stats"* ]]
+}
+
+@test "review: --branch fails for nonexistent branch" {
+  run "$LIB_DIR/archeflow-review.sh" --branch nonexistent-branch-xyz
+  [ "$status" -ne 0 ]
+  [[ "$output" == *"not found"* ]]
+}
+
+@test "review: rejects unknown arguments" {
+  run "$LIB_DIR/archeflow-review.sh" --unknown
+  [ "$status" -ne 0 ]
+  [[ "$output" == *"Unknown argument"* ]]
+}
+
+@test "review: --branch shows diff against base" {
+  # Create a feature branch with changes
+  git checkout -b feat/test-review --quiet
+  echo "feature" > feature.txt
+  git add feature.txt
+  git commit -m "feat: add feature" --quiet
+  git checkout main --quiet
+
+  run "$LIB_DIR/archeflow-review.sh" --branch feat/test-review
+  [ "$status" -eq 0 ]
+  [[ "$output" == *"feature.txt"* ]]
+}
+
+@test "review: --commit shows diff for commit range" {
+  echo "first" > first.txt
+  git add first.txt
+  git commit -m "first" --quiet
+  echo "second" > second.txt
+  git add second.txt
+  git commit -m "second" --quiet
+
+  run "$LIB_DIR/archeflow-review.sh" --commit HEAD~1..HEAD
+  [ "$status" -eq 0 ]
+  [[ "$output" == *"second.txt"* ]]
+}