Using/Teaching zone.exo instead of Far

[amessbee]

This adds code to contract file (and related deps to package.json) to use zone.exo to replace Far. Note that this is only for teaching purpose at the moment and does not make resulting contract upgradable because zone and baggage are created inside start function. The upgradability will require changing start signature which I am avoiding at the moment.

Ref(s):
Agoric/documentation#1033

[amessbee]

This can't be merged until #78 due to node version requirement for zone. @dckc

[dckc]

baggage is the 3rd arg of start. Let's go ahead and do it that way. I think it simplifies things considerably.

I'm not confident that mixing u16 and u12 dependencies is reliable.

[dckc]

What impact does this have on the contract bundle size? Does it introduce duplicate dependencies?

Other dependencies in this dapp (zoe, ertp) look like they're from u12. IME, mixing u12 and u16 is asking for trouble.

I know dapp-agoric-basics uses u14: Agoric/dapp-agoric-basics@817bc8a

Are you familiar with the fragility of dependency versions?

• bundle contains duplicated modules based on duplicated packages in node_modules agoric-sdk#8621
• fix: contract bundles have duplicate dependencies #34
• Test that compressed contract bundles are less than 1MB #36
• cannot publish inter protocol bundles over 1M due to max_tx_bytes tendermint config agoric-sdk#7501

It looks like @Jovonni managed to use u16 in dapp-orchestration-basics, though it took some troubleshooting. See item 9 in particular.

[dckc]

I gather recent symptoms include a problem when starting the ui: a blank page and a console error:

tame-console.js:159  TypeError: Cannot read properties of undefined (reading 'subscribeAfter')