feat: refactor server with shelf_static, return JSON responses, add API docs

api.md

@@ -0,0 +1,125 @@
+# API Documentation
+
+## Authentication
+
+All protected endpoints require a Bearer token in the `Authorization` header.
+
+### POST /login
+
+Authenticate with login and password.
+
+**Request Body:**
+```json
+{
+  "login": "string",
+  "password": "string"
+}
+```
+
+**Response (200):**
+```json
+{
+  "token": "string"
+}
+```
+
+**Response (401):**
+```json
+{
+  "error": "Invalid credentials"
+}
+```
+
+---
+
+### POST /reg
+
+Register a new user.
+
+**Request Body:**
+```json
+{
+  "login": "string",
+  "password": "string"
+}
+```
+
+**Response (201):**
+```json
+{
+  "message": "User registered"
+}
+```
+
+---
+
+### GET /watch?unique_id=...
+
+Get the latest position for a share link.
+
+**Response (200):**
+```json
+{
+  "x": "number",
+  "y": "number",
+  "last_update": "string",
+  "expires_at": "string"
+}
+```
+
+**Response (404):**
+```json
+{
+  "error": "Share link not found"
+}
+```
+
+---
+
+### PUT /geo?id=...
+
+Update a position.
+
+**Response (200):**
+```json
+{
+  "message": "Position updated"
+}
+```
+
+---
+
+### POST /share
+
+Create a new position with a share link.
+
+**Response (201):**
+```json
+{
+  "geo_id": "string",
+  "share_id": "string"
+}
+```
+
+---
+
+## Error Responses
+
+### Auth Middleware (401)
+```json
+{
+  "error": "Authorization header missing or invalid"
+}
+```
+
+```json
+{
+  "error": "Token expired"
+}
+```
+
+```json
+{
+  "error": "Invalid token"
+}
+```