feat(ui): add relationship management features in schema editor

- Implement functionality to create, update, delete, and view relationships between tables.
- Introduce new UI screens for managing relationships, including forms for adding and editing relationships.
- Enhance table editor with navigation to relationship management.
- Ensure relationships are displayed in a structured table format for better usability.

pkg/reflectutil/doc.go

@@ -0,0 +1,36 @@
+// Package reflectutil provides reflection utilities for analyzing Go code structures.
+//
+// # Overview
+//
+// The reflectutil package offers helper functions for working with Go's reflection
+// capabilities, particularly for parsing Go struct definitions and extracting type
+// information. This is used by readers that parse ORM model files.
+//
+// # Features
+//
+//   - Struct tag parsing and extraction
+//   - Type information analysis
+//   - Field metadata extraction
+//   - ORM tag interpretation (GORM, Bun, etc.)
+//
+// # Usage
+//
+// This package is primarily used internally by readers like GORM and Bun to parse
+// Go struct definitions and convert them to database schema models.
+//
+//	// Example: Parse struct tags
+//	tags := reflectutil.ParseStructTags(field)
+//	columnName := tags.Get("db")
+//
+// # Supported ORM Tags
+//
+// The package understands tag conventions from:
+//   - GORM (gorm tag)
+//   - Bun (bun tag)
+//   - Standard database/sql (db tag)
+//
+// # Purpose
+//
+// This package enables RelSpec to read existing ORM models and convert them to
+// a unified schema representation for transformation to other formats.
+package reflectutil