Pin Vercel OAuth callback team parameter name

The Vercel connector reads the team from the camelCase teamId callback
parameter, unlike the snake_case params most providers use. Nothing
guarded the name, so a regression back to team_id would silently drop
the team on every Vercel connect and leave the source resolving no
users.

Extract the read into vercelCallbackTeamID and pin the exact parameter
name with a test, since the surrounding handler needs a live connector
registry and database to exercise directly.

Signed-off-by: Aurélien Sibiril <81782+aureliensibiril@users.noreply.github.com>

pkg/server/api/console/v1/resolver_test.go

@@ -0,0 +1,69 @@
+// Copyright (c) 2026 Probo Inc <hello@probo.com>.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package console_v1
+
+import (
+	"net/url"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+// TestVercelCallbackTeamID pins the exact OAuth-callback query-parameter name
+// Vercel uses. It is camelCase `teamId`; a regression to the snake_case
+// `team_id` used by most other providers would silently drop the team on every
+// Vercel connect and leave the source resolving nobody.
+func TestVercelCallbackTeamID(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		name  string
+		query url.Values
+		want  string
+	}{
+		{
+			name:  "camelCase teamId is read",
+			query: url.Values{"teamId": {"team_abc123"}},
+			want:  "team_abc123",
+		},
+		{
+			name:  "snake_case team_id is ignored",
+			query: url.Values{"team_id": {"team_abc123"}},
+			want:  "",
+		},
+		{
+			name:  "absent parameter yields empty",
+			query: url.Values{},
+			want:  "",
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(
+			tc.name,
+			func(t *testing.T) {
+				t.Parallel()
+
+				assert.Equal(t, tc.want, vercelCallbackTeamID(tc.query))
+			},
+		)
+	}
+}