fix: incorrect error message on cloning unauthorized repos

[fabiovincenzi]

Fixes #1181 by implementing proper Git protocol error handling for GET /info/refs requests, replacing confusing error messages when cloning unauthorized repositories.

The issue was a Git protocol mismatch in error handling:

1. GET /info/refs requests (clone operations) require a specific error packet format (https://git-scm.com/docs/gitprotocol-pack)
2. Previous implementation used POST-oriented sideband format (\x02 + tab formatting) for all requests
3. Git client received malformed upload-pack data → parsing failed → generic "hash algorithm" error

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[codecov]

Codecov Report

❌ Patch coverage is 88.88889% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 83.86%. Comparing base (6ee5f0b) to head (fadf820).
⚠️ Report is 11 commits behind head on main.

Files with missing lines	Patch %	Lines
src/proxy/routes/index.ts	88.88%	3 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1204      +/-   ##
==========================================
+ Coverage   83.72%   83.86%   +0.13%     
==========================================
  Files          67       67              
  Lines        2888     2906      +18     
  Branches      366      366              
==========================================
+ Hits         2418     2437      +19     
+ Misses        410      409       -1     
  Partials       60       60              

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[kriswest]

Great work figuring this out! I've dug out some more info on when requests to /info/refs occur, to inform comments and think you should make a function name more specific - but otherwise very happy to see this solved.

[kriswest]

I just realized the catch statement down on line 103 of src/proxy/routes/index.ts should probably do the same check and use the response format - that handles uncaught errors thrown while running the chain. Not critical but more complete?

[fabiovincenzi]

I just realized the catch statement down on line 103 of src/proxy/routes/index.ts should probably do the same check and use the response format - that handles uncaught errors thrown while running the chain. Not critical but more complete?

You are right! @kriswest

[kriswest]

One thing to simplify, otherwise LGTM!

[jescalada]

Tested the original flow and works fine, LGTM after fixing up Kris' comments! 🚀

[kriswest]

Happy with this.