Summary
relax clangd initialize capability checks to tolerate valid response shape differences
add a clangd-specific document-symbol cache fingerprint so stale C++ symbol caches are invalidated when backend/config state changes
add a regression test covering C++ document-symbol cache invalidation
Problem
For C++ projects, Serena's symbol tools could keep returning malformed cached document symbols even after clangd / compile commands / backend state had been repaired. The cache key was effectively stable as long as file contents did not change, so previously bad symbol trees could survive later LS recovery.
In addition, clangd capability checks were too strict and assumed a single exact initialize-response shape.
What this changes
accepts both integer and object-style textDocumentSync responses
validates completionProvider more conservatively by checking required trigger characters instead of exact equality
fingerprints clangd document-symbol caches using:
clangd_version
ls_path
compile_commands_dir
compile_commands.json content hash
adds a C++ regression test similar to the existing Go cache invalidation coverage
Adds tests for name resolution for each language and fixes the name resolution where tests have failed.
Also:
Extends python tests to cover ty
Extends skipping conditions for several LS (but only when not in CI)
Better test output in CI
Removed a wrong python test (started failing for ty and should have failed for pyright too)
Black dependency created a dependabot warning and couldn't be bumped since it collided with pathspec dependencies. Since ruff can also format, black is not needed. But we now have these small format changes, mostly in test files
Fixes longstanding clangd issues (wrong selectionRange, failure to take compile_commands.json into account) and enhances documentation about C/C++ support
