Add Debug Logs for thv run Server Location

[jerm-dro]

Summary

Add debug logs that differentiate which type of MCP server we're attempting to run.

Fixes #2761

Implementation Details

The linked issue gestures towards an ideal solution where we have one log per type of MCP server. The existing code branches in quite a few places (e.g. there are two different paths for differentiating between remote and registry MCP servers). Instead of adding logging to these cases exhaustively, I opted to make an incremental improvement in the debug logs.

I'd prefer to consolidate the existing code into fewer branches before adding more logs, but if someone feels strongly LMK and I can accommodate.

Testing

I verified the new logs appear locally by running task build and then a series of bin/thv run --debug commands. Output pictured below:

[codecov]

Codecov Report

❌ Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 56.61%. Comparing base (f0ce9c2) to head (5a9a1ce).
⚠️ Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/runner/retriever/retriever.go	50.00%	1 Missing ⚠️

Additional details and impacted files

@@ Coverage Diff @@ ## main #2834 +/- ## ======================================= Coverage 56.61% 56.61% ======================================= Files 320 320 Lines 30932 30933 +1 ======================================= + Hits 17511 17513 +2  + Misses 11916 11915 -1  Partials 1505 1505 

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[eleftherias]

Thanks for the PR @jerm-dro!
I added some comments about the nuances between registry servers, remote servers, and images.