feat(setup): T01 create project directory structure

- Create src/openrouter_monitor/ package structure
- Create models/, routers/, services/, utils/ subpackages
- Create tests/unit/ and tests/integration/ structure
- Create alembic/, docs/, scripts/ directories
- Add test_project_structure.py with 13 unit tests
- All tests passing (13/13)

Refs: T01

.opencode/opencode.json

@@ -0,0 +1,29 @@
+{
+  "$schema": "https://opencode.ai/config.json",
+  "mcp": {
+    "sequential-thinking": {
+      "type": "local",
+      "command": [
+        "npx",
+        "-y",
+        "@modelcontextprotocol/server-sequential-thinking"
+      ]
+    },
+    "context7": {
+      "type": "local",
+      "command": [
+        "npx",
+        "-y",
+        "@context7/mcp-server"
+      ]
+    },
+    "universal-skills": {
+      "type": "local",
+      "command": [
+        "npx",
+        "-y",
+        "github:jacob-bd/universal-skills-manager"
+      ]
+    }
+  }
+}