Fix 'Why TEE' body copy — governability, not ungovernability

The original 'ungovernability' was reaching for 'cannot be censored
or unilaterally changed' but it lands as a negative non-feature and
also misses the real point: Lit Actions ARE governed on-chain — by
whatever governance the operator wires up (multisig, DAO, contract).
'On-chain governability' captures the actual property.

Author: glitch003

src/components/LandingHowItWorks/LandingHowItWorks.tsx

@@ -116,7 +116,7 @@ const LandingHowItWorks = () => {
               The TEE's identity, its allowed code, and its signing
               authority are all governed by a chain. You get the speed and
               expressiveness of a single trusted runtime, with the
-              auditability and ungovernability of a smart contract.
+              auditability and on-chain governability of a smart contract.
             </p>
           </div>
         </Container>

src/components/Prototypes/Prototype1.tsx

@@ -142,7 +142,7 @@ export default function Prototype1() {
               The TEE's identity, its allowed code, and its signing
               authority are all governed by a chain. You get the speed and
               expressiveness of a single trusted runtime, with the auditability
-              and ungovernability of a smart contract.
+              and on-chain governability of a smart contract.
             </p>
           </div>
         </Container>