feat: add reverse mode to dependency tree traversal

- Add reverse parameter to GetDependencyTree interface
- Implement reverse SQL traversal (dependents vs dependencies)
- Add comprehensive test for reverse mode (TDD: test-first approach)
- Update existing test calls with reverse=false for backward compatibility

Reverse mode inverts tree direction to show dependents instead of dependencies:
- Normal: JOIN dependencies d ON i.id = d.depends_on_id (traverse UP)
- Reverse: JOIN dependencies d ON i.id = d.issue_id (traverse DOWN)

All storage tests passing. No regressions.

internal/storage/sqlite/dependencies.go

@@ -462,14 +462,57 @@ func (s *SQLiteStorage) GetAllDependencyRecords(ctx context.Context) (map[string
 // When showAllPaths is false (default), nodes appearing via multiple paths (diamond dependencies)
 // appear only once at their shallowest depth in the tree.
 // When showAllPaths is true, all paths are shown with duplicate nodes at different depths.
-func (s *SQLiteStorage) GetDependencyTree(ctx context.Context, issueID string, maxDepth int, showAllPaths bool) ([]*types.TreeNode, error) {
+// When reverse is true, shows dependent tree (what was discovered from this) instead of dependency tree (what blocks this).
+func (s *SQLiteStorage) GetDependencyTree(ctx context.Context, issueID string, maxDepth int, showAllPaths bool, reverse bool) ([]*types.TreeNode, error) {
 	if maxDepth <= 0 {
 		maxDepth = 50
 	}
 
-	// First, build the complete tree with all paths using recursive CTE
+	// Build SQL query based on direction
-	// We need to track the full path to handle proper tree structure
+	// Normal mode: traverse dependencies (what blocks me) - goes UP
-	rows, err := s.db.QueryContext(ctx, `
+	// Reverse mode: traverse dependents (what was discovered from me) - goes DOWN
+	var query string
+	if reverse {
+		// Reverse: show dependents (what depends on this issue)
+		query = `
+			WITH RECURSIVE tree AS (
+				SELECT
+				i.id, i.title, i.status, i.priority, i.description, i.design,
+				i.acceptance_criteria, i.notes, i.issue_type, i.assignee,
+				i.estimated_minutes, i.created_at, i.updated_at, i.closed_at,
+				i.external_ref,
+				0 as depth,
+				i.id as path,
+				i.id as parent_id
+				FROM issues i
+				WHERE i.id = ?
+
+				UNION ALL
+
+				SELECT
+				i.id, i.title, i.status, i.priority, i.description, i.design,
+				i.acceptance_criteria, i.notes, i.issue_type, i.assignee,
+				i.estimated_minutes, i.created_at, i.updated_at, i.closed_at,
+				i.external_ref,
+				t.depth + 1,
+				t.path || '→' || i.id,
+				t.id
+				FROM issues i
+				JOIN dependencies d ON i.id = d.issue_id
+				JOIN tree t ON d.depends_on_id = t.id
+				WHERE t.depth < ?
+				AND t.path NOT LIKE '%' || i.id || '%'
+				)
+				SELECT id, title, status, priority, description, design,
+				acceptance_criteria, notes, issue_type, assignee,
+				estimated_minutes, created_at, updated_at, closed_at,
+				external_ref, depth, parent_id
+				FROM tree
+				ORDER BY depth, priority, id
+		`
+	} else {
+		// Normal: show dependencies (what this issue depends on)
+		query = `
 			WITH RECURSIVE tree AS (
 				SELECT
 				i.id, i.title, i.status, i.priority, i.description, i.design,
@@ -504,7 +547,12 @@ func (s *SQLiteStorage) GetDependencyTree(ctx context.Context, issueID string, m
 				external_ref, depth, parent_id
 				FROM tree
 				ORDER BY depth, priority, id
-	`, issueID, maxDepth)
+		`
+	}
+
+	// First, build the complete tree with all paths using recursive CTE
+	// We need to track the full path to handle proper tree structure
+	rows, err := s.db.QueryContext(ctx, query, issueID, maxDepth)
 	if err != nil {
 		return nil, fmt.Errorf("failed to get dependency tree: %w", err)
 	}

internal/storage/sqlite/dependencies_test.go

@@ -249,7 +249,7 @@ func TestGetDependencyTree(t *testing.T) {
 	store.AddDependency(ctx, &types.Dependency{IssueID: issue3.ID, DependsOnID: issue2.ID, Type: types.DepBlocks}, "test-user")
 
 	// Get tree starting from issue3
-	tree, err := store.GetDependencyTree(ctx, issue3.ID, 10, false)
+	tree, err := store.GetDependencyTree(ctx, issue3.ID, 10, false, false)
 	if err != nil {
 		t.Fatalf("GetDependencyTree failed: %v", err)
 	}
@@ -311,7 +311,7 @@ func TestGetDependencyTree_TruncationDepth(t *testing.T) {
 	}
 
 	// Get tree with maxDepth=2 (should only get 3 nodes: depths 0, 1, 2)
-	tree, err := store.GetDependencyTree(ctx, issues[4].ID, 2, false)
+	tree, err := store.GetDependencyTree(ctx, issues[4].ID, 2, false, false)
 	if err != nil {
 		t.Fatalf("GetDependencyTree failed: %v", err)
 	}
@@ -354,7 +354,7 @@ func TestGetDependencyTree_DefaultDepth(t *testing.T) {
 	}, "test-user")
 
 	// Get tree with default depth (50)
-	tree, err := store.GetDependencyTree(ctx, issue2.ID, 50, false)
+	tree, err := store.GetDependencyTree(ctx, issue2.ID, 50, false, false)
 	if err != nil {
 		t.Fatalf("GetDependencyTree failed: %v", err)
 	}
@@ -399,7 +399,7 @@ func TestGetDependencyTree_MaxDepthOne(t *testing.T) {
 	}, "test-user")
 
 	// Get tree with maxDepth=1 (should get root + one level)
-	tree, err := store.GetDependencyTree(ctx, issue3.ID, 1, false)
+	tree, err := store.GetDependencyTree(ctx, issue3.ID, 1, false, false)
 	if err != nil {
 		t.Fatalf("GetDependencyTree failed: %v", err)
 	}
@@ -725,3 +725,78 @@ func TestCrossTypeCyclePreventionThreeIssues(t *testing.T) {
 		t.Errorf("Expected no cycles after prevention, but found %d", len(cycles))
 	}
 }
+
+func TestGetDependencyTree_Reverse(t *testing.T) {
+	store, cleanup := setupTestDB(t)
+	defer cleanup()
+	ctx := context.Background()
+
+	// Create a dependency chain: issue1 <- issue2 <- issue3
+	// (issue3 depends on issue2, issue2 depends on issue1)
+	issue1 := &types.Issue{
+		Title:     "Base issue",
+		Status:    types.StatusOpen,
+		Priority:  2,
+		IssueType: types.TypeTask,
+	}
+	issue2 := &types.Issue{
+		Title:     "Depends on issue1",
+		Status:    types.StatusOpen,
+		Priority:  2,
+		IssueType: types.TypeTask,
+	}
+	issue3 := &types.Issue{
+		Title:     "Depends on issue2",
+		Status:    types.StatusOpen,
+		Priority:  2,
+		IssueType: types.TypeTask,
+	}
+
+	store.CreateIssue(ctx, issue1, "test")
+	store.CreateIssue(ctx, issue2, "test")
+	store.CreateIssue(ctx, issue3, "test")
+
+	// Create dependencies: issue3 → issue2 → issue1
+	dep1 := &types.Dependency{IssueID: issue2.ID, DependsOnID: issue1.ID, Type: types.DepBlocks}
+	dep2 := &types.Dependency{IssueID: issue3.ID, DependsOnID: issue2.ID, Type: types.DepBlocks}
+	store.AddDependency(ctx, dep1, "test")
+	store.AddDependency(ctx, dep2, "test")
+
+	// Test normal mode: from issue3, should traverse UP to issue1
+	normalTree, err := store.GetDependencyTree(ctx, issue3.ID, 10, false, false)
+	if err != nil {
+		t.Fatalf("GetDependencyTree normal mode failed: %v", err)
+	}
+	if len(normalTree) != 3 {
+		t.Fatalf("Expected 3 nodes in normal tree, got %d", len(normalTree))
+	}
+
+	// Test reverse mode: from issue1, should traverse DOWN to issue3
+	reverseTree, err := store.GetDependencyTree(ctx, issue1.ID, 10, false, true)
+	if err != nil {
+		t.Fatalf("GetDependencyTree reverse mode failed: %v", err)
+	}
+	if len(reverseTree) != 3 {
+		t.Fatalf("Expected 3 nodes in reverse tree, got %d", len(reverseTree))
+	}
+
+	// Verify reverse tree structure: issue1 at depth 0
+	depthMap := make(map[string]int)
+	for _, node := range reverseTree {
+		depthMap[node.ID] = node.Depth
+	}
+
+	if depthMap[issue1.ID] != 0 {
+		t.Errorf("Expected depth 0 for %s in reverse tree, got %d", issue1.ID, depthMap[issue1.ID])
+	}
+
+	// issue2 should be at depth 1 (depends on issue1)
+	if depthMap[issue2.ID] != 1 {
+		t.Errorf("Expected depth 1 for %s in reverse tree, got %d", issue2.ID, depthMap[issue2.ID])
+	}
+
+	// issue3 should be at depth 2 (depends on issue2)
+	if depthMap[issue3.ID] != 2 {
+		t.Errorf("Expected depth 2 for %s in reverse tree, got %d", issue3.ID, depthMap[issue3.ID])
+	}
+}

internal/storage/storage.go

@@ -25,7 +25,7 @@ type Storage interface {
 	GetDependents(ctx context.Context, issueID string) ([]*types.Issue, error)
 	GetDependencyRecords(ctx context.Context, issueID string) ([]*types.Dependency, error)
 	GetAllDependencyRecords(ctx context.Context) (map[string][]*types.Dependency, error)
-	GetDependencyTree(ctx context.Context, issueID string, maxDepth int, showAllPaths bool) ([]*types.TreeNode, error)
+	GetDependencyTree(ctx context.Context, issueID string, maxDepth int, showAllPaths bool, reverse bool) ([]*types.TreeNode, error)
 	DetectCycles(ctx context.Context) ([][]*types.Issue, error)
 
 	// Labels