feat(sync)!: replace per-entity sync RPC with TeamConfigRecord blobs

Cloud sync now exchanges opaque TeamConfigRecord envelopes (kind + ciphertext
payload) instead of typed Host/SshKey/Identity/KnownHost/PortForward message sets.

BREAKING CHANGE: SyncConfigResponse drops hostSet/sshKeySet/etc. in favor of
records; UpdateConfigRequest/Response use team_id + TeamConfigRecord only.
Existing sync clients and termium-be must upgrade together with this proto.

Author: asjdf

gen/openapi/sync/v1/config_body.swagger.json

@@ -0,0 +1,44 @@
+{
+  "swagger": "2.0",
+  "info": {
+    "title": "sync/v1/config_body.proto",
+    "version": "version not set"
+  },
+  "consumes": [
+    "application/json"
+  ],
+  "produces": [
+    "application/json"
+  ],
+  "paths": {},
+  "definitions": {
+    "protobufAny": {
+      "type": "object",
+      "properties": {
+        "@type": {
+          "type": "string"
+        }
+      },
+      "additionalProperties": {}
+    },
+    "rpcStatus": {
+      "type": "object",
+      "properties": {
+        "code": {
+          "type": "integer",
+          "format": "int32"
+        },
+        "message": {
+          "type": "string"
+        },
+        "details": {
+          "type": "array",
+          "items": {
+            "type": "object",
+            "$ref": "#/definitions/protobufAny"
+          }
+        }
+      }
+    }
+  }
+}