feat(psn): link PlayStation account and import played games

The NPSSO is used once to get a refresh token; only that token is
stored, sealed with AES-GCM (SecretBox, key APP_PSN_TOKEN_KEY; no key
= feature off). One-time import of played PS4/PS5 titles through the
import pipeline as source PSN. Unlink keeps the games. One PSN call
per user at a time. IGDB search now sends UTF-8, so non-ASCII names
like "Yōtei" match again.

local/wiremock/mappings/psn-token.json

@@ -0,0 +1,13 @@
+{
+  "request": {
+    "method": "POST",
+    "urlPath": "/psn/auth/token"
+  },
+  "response": {
+    "status": 200,
+    "headers": {
+      "Content-Type": "application/json"
+    },
+    "bodyFileName": "psn-token.json"
+  }
+}