feat: implement project status management with 'on_hold' state and associated UI updates

-feat: ability to hard delete projects, plus a soft delete with auto pruning.

backend/migrate_add_project_deleted_at.py

@@ -0,0 +1,56 @@
+"""
+Migration: Add deleted_at column to projects table
+
+Adds columns:
+- projects.deleted_at: Timestamp set when status='deleted'; data hard-deleted after 60 days
+"""
+
+import sqlite3
+import sys
+from pathlib import Path
+
+
+def migrate(db_path: str):
+    """Run the migration."""
+    print(f"Migrating database: {db_path}")
+
+    conn = sqlite3.connect(db_path)
+    cursor = conn.cursor()
+
+    try:
+        cursor.execute("SELECT name FROM sqlite_master WHERE type='table' AND name='projects'")
+        if not cursor.fetchone():
+            print("projects table does not exist. Skipping migration.")
+            return
+
+        cursor.execute("PRAGMA table_info(projects)")
+        existing_cols = {row[1] for row in cursor.fetchall()}
+
+        if 'deleted_at' not in existing_cols:
+            print("Adding deleted_at column to projects...")
+            cursor.execute("ALTER TABLE projects ADD COLUMN deleted_at DATETIME")
+        else:
+            print("deleted_at column already exists. Skipping.")
+
+        conn.commit()
+        print("Migration completed successfully!")
+
+    except Exception as e:
+        print(f"Migration failed: {e}")
+        conn.rollback()
+        raise
+    finally:
+        conn.close()
+
+
+if __name__ == "__main__":
+    db_path = "./data/terra-view.db"
+
+    if len(sys.argv) > 1:
+        db_path = sys.argv[1]
+
+    if not Path(db_path).exists():
+        print(f"Database not found: {db_path}")
+        sys.exit(1)
+
+    migrate(db_path)