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-76293a500bb01e184759b8b2f1216645776380fda0f84d2f53f408b3bc5ff035.json

@@ -0,0 +1,20 @@
+{
+  "db_name": "PostgreSQL",
+  "query": "SELECT COUNT(*)::int as \"count!\" FROM tags",
+  "describe": {
+    "columns": [
+      {
+        "ordinal": 0,
+        "name": "count!",
+        "type_info": "Int4"
+      }
+    ],
+    "parameters": {
+      "Left": []
+    },
+    "nullable": [
+      null
+    ]
+  },
+  "hash": "76293a500bb01e184759b8b2f1216645776380fda0f84d2f53f408b3bc5ff035"
+}