[SAI_Peregrinus]

A HWRNG is not necessarily a TRNG. As you say, a TRNG has one bit of entropy per bit of output. There's no way to prove this property is even possible in this physical universe, since it requires perfect unpredictability. Urandom is a CSPRNG seeded by a HWRNG.

[pclmulqdq]

This is true. The Intel HWRNG has actually been thought to be suspect in this regard in the past, although I don't think there's actual data about that.

Urandom also takes entropy from things like mouse movements, inter-onset intervals of key presses, and (on servers) hard drive seek times, so it actually does take in some of its own entropy in addition to that provided by the CPU.