feat: add PostgreSQL database integration for projects

- Add SQLx with Postgres support and migration system
- Create projects table with status enum and auto-updated timestamps
- Implement database queries and API response conversion layer
- Add Justfile commands for database management and seeding
- Integrate health checks for both Bun and database connectivity

.sqlx/query-42799df09f28f38b73c4a0f90516dc432e7660d679d3ce8eb448cde2dad81608.json

@@ -0,0 +1,20 @@
+{
+  "db_name": "PostgreSQL",
+  "query": "SELECT 1 as check",
+  "describe": {
+    "columns": [
+      {
+        "ordinal": 0,
+        "name": "check",
+        "type_info": "Int4"
+      }
+    ],
+    "parameters": {
+      "Left": []
+    },
+    "nullable": [
+      null
+    ]
+  },
+  "hash": "42799df09f28f38b73c4a0f90516dc432e7660d679d3ce8eb448cde2dad81608"
+}