docs: add lic server api spec and index in second brain

.brain/index.md

@@ -2,3 +2,4 @@
 
 - [Supabase Schema](file:///c:/source/webshop/.brain/supabase-schema.md)
 - [ADR Log](file:///c:/source/webshop/.brain/adr-log.md)
+- [LicServer API Spezifikation](file:///c:/source/webshop/.brain/licserver-api.md)

.brain/licserver-api.md

@@ -0,0 +1,114 @@
+# LicServer API Spezifikation (v1)
+
+Dokumentation der REST-Schnittstellen des CASPOS Lizenzservers (`http://192.168.178.174:9981`).
+
+## 1. Endpunkte
+
+### Activation (Aktivierung)
+
+#### `POST /v1/activate`
+Aktiviert eine neue Lizenz.
+
+**Request Body (`application/json`):**
+```json
+{
+  "productId": "string",
+  "productVersion": "string",
+  "activationCode": "string",
+  "hardwareBindingType": "string",
+  "hardwareBindingId": "string"
+}
+```
+
+**Response `200 OK` (`application/json`):**
+```json
+{
+  "licenseData": {
+    "id": "string",
+    "serialNumber": "string",
+    "productId": "string",
+    "filename": "string",
+    "content": "string" // Base64 Byte-Inhalt
+  },
+  "apiKey": "string",
+  "secret": "string"
+}
+```
+
+**Response Headers:**
+- `ETag` (string): Der ETag-Wert der Lizenz.
+
+---
+
+#### `POST /v1/activate-existing`
+Aktiviert eine bereits vorhandene Lizenz erneut.
+
+**Request Body (`application/json`):**
+```json
+{
+  "productId": "string",
+  "productVersion": "string",
+  "serialNumber": "string",
+  "proofOfPossessionHash": "string",
+  "salt": "string",
+  "hardwareBindingType": "string",
+  "hardwareBindingId": "string"
+}
+```
+
+**Response `200 OK` (`application/json`):**
+*Gleiche Struktur wie bei `/v1/activate`.*
+
+---
+
+### Licenses (Lizenzen)
+
+#### `GET /v1/licenses/{id}`
+Holt die Lizenz-Details zu einer bestimmten Lizenz-ID.
+
+**Request Parameters:**
+- `id` (path, string, required): Die UUID der Lizenz.
+- `If-None-Match` (header, string, optional): ETag zur Cache-Validierung.
+
+**Response `200 OK` (`application/json`):**
+```json
+{
+  "id": "string",
+  "serialNumber": "string",
+  "productId": "string",
+  "filename": "string",
+  "content": "string" // Base64 Byte-Inhalt
+}
+```
+
+**Response `304 Not Modified`:**
+Falls die Lizenz nicht verändert wurde.
+
+**Response `404 Not Found` / `403 Forbidden`:**
+Standard Fehlerobjekt `ProblemDetails`.
+
+---
+
+## 2. Typen & Schemas
+
+### `LicenseData`
+```json
+{
+  "id": "string",
+  "serialNumber": "string",
+  "productId": "string",
+  "filename": "string",
+  "content": "string" // Base64 Byte-Inhalt
+}
+```
+
+### `ProblemDetails`
+```json
+{
+  "type": "string",
+  "title": "string",
+  "status": 0,
+  "detail": "string",
+  "instance": "string"
+}
+```