chore: add custom samesite options to auth cookies (#16885)

Allows controlling `samesite` cookie settings from the deployment config

cli/server.go

@@ -641,7 +641,6 @@ func (r *RootCmd) Server(newAPI func(context.Context, *coderd.Options) (*coderd.
 				GoogleTokenValidator:        googleTokenValidator,
 				ExternalAuthConfigs:         externalAuthConfigs,
 				RealIPConfig:                realIPConfig,
-				SecureAuthCookie:            vals.SecureAuthCookie.Value(),
 				SSHKeygenAlgorithm:          sshKeygenAlgorithm,
 				TracerProvider:              tracerProvider,
 				Telemetry:                   telemetry.NewNoop(),

cli/testdata/coder_server_--help.golden

@@ -251,6 +251,9 @@ NETWORKING OPTIONS:
           Specifies whether to redirect requests that do not match the access
           URL host.
 
+      --samesite-auth-cookie lax|none, $CODER_SAMESITE_AUTH_COOKIE (default: lax)
+          Controls the 'SameSite' property is set on browser session cookies.
+
       --secure-auth-cookie bool, $CODER_SECURE_AUTH_COOKIE
           Controls if the 'Secure' property is set on browser session cookies.
 

cli/testdata/server-config.yaml.golden

@@ -174,6 +174,9 @@ networking:
   # Controls if the 'Secure' property is set on browser session cookies.
   # (default: <unset>, type: bool)
   secureAuthCookie: false
+  # Controls the 'SameSite' property is set on browser session cookies.
+  # (default: lax, type: enum[lax\|none])
+  sameSiteAuthCookie: lax
   # Whether Coder only allows connections to workspaces via the browser.
   # (default: <unset>, type: bool)
   browserOnly: false