[33.0-beta0] | ScriptBuf Tag Types + Rust Miniscript Integration

Problem

Currently I am attempting a refactor of rust-miniscript library to enable BIP-0390 musig descriptor support.

Schnorr Pk agg is not a part of rust-bitcoin 31.x FFI bindings in libsecp256k1 this leads to a problem. Updating to version 33.0-beta0 which supports these bindings uses a new tagged version of ScriptBuf which is hard to refactor into locations like this ... RustMsiniscript Bare

Where the above function does not fit the model of any of the available tags this is because the above function should return a script buffer that can be used either as a ScriptSig element or a WitnessScript which each have their own tags but not a mixed tag that represent multiple locations for use.

Example.
https://github.com/rust-bitcoin/rust-bitcoin/blob/4f84103e6a04e93f26122e2e7e272f6ce3f378e1/primitives/src/script/mod.rs#L56-L65

https://github.com/rust-bitcoin/rust-bitcoin/blob/4f84103e6a04e93f26122e2e7e272f6ce3f378e1/primitives/src/script/tag.rs#L9-L39

Thanks in advance,
PortlandHODL

Start with rust-miniscript's src/descriptor/bare.rs and compare its ScriptBuf use with rust-bitcoin's primitives/src/script/mod.rs and primitives/src/script/tag.rs. Read the linked MuSig FFI context to understand the 33.0-beta0 constraint and determine how the bare descriptor output should represent both ScriptSig and WitnessScript uses. Done means an agreed ScriptBuf tagging approach that supports this integration without misrepresenting the script's valid contexts.