Remove stage 2 and replace w/ a static docker registry implementation in rust

[Noxsios]

Description

Replaces the 2-stage injector systems with a single Rust binary that:

1. assembles the configmap chunks
2. extracts the archive
3. validates the payload shasum
4. serves the image via an embedded OCI distribution endpoint in Rust

Related Issue

Fixes #708

Type of change

• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist before merging

• Tests have been added/updated as necessary (add the needs-tests label)
• Documentation has been updated as necessary (add the needs-docs label)
• An ADR has been written as necessary (add the needs-adr label) [ 1 2 3 ]
• (Optional) Changes have been linted locally with golangci-lint. (NOTE: We haven't turned on lint checks in the pipeline yet so linting may be hard if it shows a lot of lint errors in places that weren't touched by changes. Thus, linting is optional right now.)

[Racer159]

Small stuff looking through the code

[jeff-mccoy]

We won't be able to merge this until it is off of nightly, have you tried evaluating with MUSL or do you have a better idea when they will call this magic binary shrinking fun stable?

[Noxsios]

To replicate (currently) working w/ a local built binary:

cd src/injector/stage1
./release.sh
cd ../../../
make init-package
make build-cli-mac-apple ARCH=arm64
cd build
# <blah blah> = ./zarf-mac-apple version
zarf tools archiver decompress zarf-init-arm64-v0.22.2-<blah blah>.tar.zst init
cp ../src/injector/stage1/target/aarch64-unknown-linux-musl/release/zarf-injector init/components/zarf-injector/files/0
rm zarf-init-arm64-*
zarf tools archiver compress init/. zarf-init-arm64-<blah blah>.tar.zst
./zarf-mac-apple init -l=trace

[Noxsios]

Current sizes w/ stable optimizations:

x86_64 binary size: 873k
aarch64 binary size: 750k

[Madeline-UX]

@Noxsios can you point me to the docs you created for this? I can support you by helping review those.

[jeff-mccoy]

@Noxsios as you test the local distros, please drop a screenshot in this PR and note the distribution, thanks.

[Noxsios]

@Noxsios as you test the local distros, please drop a screenshot in this PR and note the distribution, thanks.

❌ Microk8s: Unable to deploy due to not supporting http docker registries. Regular zarf init from master branch also failed, so this is more of zarf not working on Microk8s and less the changes in this PR.

📍 TKG: TKG community edition got nuked. Will attempt and update w/ "free" TKG download.

❌ AKS: AKS is very broken.

✅ Docker Desktop K8s: working flawlessly.

[jeff-mccoy]

Confirmed the injector functioned properly in EKS in addition to local clusters already tested.

[jeff-mccoy]

Overall lgtm, already made most of the changes I wanted to see in the other PR that was merged into this one. Only area I'd like to leave as a future thing to look at is the FormatCraneOCILayout function. Think there's some things we can do to clean that up, especially when it comes to manually defining the struct vs using an existing library we likely already import (go-containertools or registry).

Correction made.