refactor: implement full projects CRUD, move icons onto tag schema

- Remove priority field and sorting, switch to updated_at DESC
- Add icon field to tags table
- Split project description into name and short_description
- Implement full CRUD for projects (create, update, delete)
- Add admin stats endpoint (project counts by status)

.sqlx/query-a5ba908419fb3e456bdd2daca41ba06cc3212ffffb8520fc7dbbcc8b60ada314.json

@@ -0,0 +1,14 @@
+{
+  "db_name": "PostgreSQL",
+  "query": "DELETE FROM projects WHERE id = $1",
+  "describe": {
+    "columns": [],
+    "parameters": {
+      "Left": [
+        "Uuid"
+      ]
+    },
+    "nullable": []
+  },
+  "hash": "a5ba908419fb3e456bdd2daca41ba06cc3212ffffb8520fc7dbbcc8b60ada314"
+}