parse_budget_timeout

Lexing, parsing, or a parse subprocess for a single `.rq` file must finish within a wall-clock budget.
If it cannot, do not hang the language server or block the rest of the workspace.
Surface both a warning ( budget exceeded; semantic features may be incomplete ) and an error ( file left unloaded ) on that document, then continue with other files.
Happy path stays in-process ( sync ) for typical file sizes so edits and workspace load stay fast.
Killable worker enforcement is used when the input is large, a file previously hit the budget ( sticky escalate ), or a caller forces the worker path; sync throws still become the same incomplete result shape.

Status: done

Interactive page: parse_budget_timeout