Offer more formats than astring for pre-commit and post-checkout

[jsinterface]

current support is only for committing in astring's format, while original authoring is in aphoristic tacit, but there might be popular demand for eg. prettier too...

[jsinterface]

pre-commit (and corresponding post-commit) hook exists, but needs to support more formats:
https://github.com/jsinterface/interface/blob/stable/Blik_2023_git_hook_pre-commit.sh
https://github.com/jsinterface/interface/blob/stable/Blik_2023_git_hook_post-commit.sh

post-checkout hook would be the inverse of pre-commit (to/from conventional format).
Conventional format should be hard-coded in source definition (bundle root may need to be identified with static/scope network).
Preferred format may be parameterized like the host protocol (db or JSON keystore).

server repositories may get their own formatters too in post-receive:
https://github.com/jsinterface/form/blob/stable/Blik_2025_git_hook_post-receive.sh

draft formatter composition is currently located in Interface:

interface/Blik_2023_interface.js

Line 681 in 7e61177

export var compile=compose(drop(1),load,parse,serialize);

Interface/load may suffice with its context argument, but the only reason that loader hook doesn't return only an AST is the lack of modular runtime evaluator in Nodejs (separate load+modularise instead of redundant parsing in both).
The intent should therefore remain to compose it with meta/serialize explicitly.
Load should rather be adopted to return an AST for non-loaderhook usage (when next?.name!=="nextLoad")

Ideally, the hooks are also rewritten for !#node hashbang with eg. https://github.com/isomorphic-git/isomorphic-git, since it will be needed for exposing file history in the Static route module.