Better error reporting

[Hoblovski]

Goal: improved error reporting for more ergonomic use.

Tasks:

• Suppress the "token not found", "dep not found" in output messages.
• In Parse(), detect when lspPath is "" but an LSP is required for subsequent collection. This is the root cause of CI panic here, where clangd is not installed but abcoder does not emit proper hints.
• MORE here.