fix: Drop the anonymous namespace from the benchmark URI

[chfast]

Related to #40.

extract_lambda_namespace() rejects a namespace containing (anonymous namespace), which is how clang spells it, but GCC spells it {anonymous} and that spelling passes the check unnoticed. The benchmarks registered inside an anonymous namespace therefore end up reported as file.cpp::{anonymous}::bench[…] with GCC, and as file.cpp::bench[…] plus an [ERROR] Anonymous namespace not supported line per benchmark with clang.

Since an anonymous namespace is not part of any identifier a benchmark can be referred to by, this strips the segment instead of bailing out, handling both spellings. The rest of the namespace path is preserved, so {anonymous}::outer:: becomes outer::, and nothing is reported for a construct that is merely unnameable rather than unsupported.

[greptile-apps]

Greptile Summary

This PR normalizes benchmark namespace extraction across GCC and Clang by removing compiler-specific anonymous-namespace segments instead of rejecting them.

• Adds a helper that removes both GCC and Clang anonymous-namespace spellings.
• Applies normalization after compiler-specific namespace extraction.
• Removes the obsolete error output and <iostream> dependency.

Confidence Score: 5/5

The PR appears safe to merge with no actionable correctness or security issues identified.

The normalization removes only compiler-generated strings that cannot be valid C++ namespace identifiers, while retaining the source-file and named-namespace portions used to identify benchmarks.

Important Files Changed

Filename	Overview
core/src/uri.cpp	Anonymous namespace markers are consistently removed while preserving source-file and named-namespace components of benchmark URIs.

_{Reviews (1): Last reviewed commit: "fix: Drop the anonymous namespace from t..." | Re-trigger Greptile}