feat(google_drive): use oauth2 crate for PKCE support, make token storage generic over Serializable (#1645)

Cargo.lock

@@ -2420,6 +2420,7 @@ dependencies = [
  "lopdf",
  "mcp-core",
  "mcp-server",
+ "oauth2",
  "once_cell",
  "regex",
  "reqwest 0.11.27",
@@ -3920,6 +3921,26 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "830b246a0e5f20af87141b25c173cd1b609bd7779a4617d6ec582abaf90870f3"
 
+[[package]]
+name = "oauth2"
+version = "5.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "51e219e79014df21a225b1860a479e2dcd7cbd9130f4defd4bd0e191ea31d67d"
+dependencies = [
+ "base64 0.22.1",
+ "chrono",
+ "getrandom 0.2.15",
+ "http 1.2.0",
+ "rand",
+ "reqwest 0.12.12",
+ "serde",
+ "serde_json",
+ "serde_path_to_error",
+ "sha2",
+ "thiserror 1.0.69",
+ "url",
+]
+
 [[package]]
 name = "objc"
 version = "0.2.7"
@@ -6200,6 +6221,7 @@ dependencies = [
  "form_urlencoded",
  "idna",
  "percent-encoding",
+ "serde",
 ]
 
 [[package]]