fix(lsp): address codex review round 3

Final review pass on the local provider:
- Tear the instance down when `initialize` REJECTS (utf-8 negotiation, malformed
  result), not only on abort, so a permanently-rejecting `ready` is never pooled.
- Use the group-aware SIGKILL on a framing failure so helpers are reached.
- Validate maxMessageBytes and maxDocumentBytes positive at load alongside the
  other byte caps.
- Fix the location renderer's outside-workspace check to match a `..` segment
  exactly, so an in-workspace path like `..generated/a.ts` stays relative.
- Document the accepted ancestor-directory symlink-swap TOCTOU under the
  trusted-host model (O_NOFOLLOW guards only the final component).

packages/lsp/tool-lsp/src/render.ts

@@ -137,7 +137,9 @@ export function renderUri(uri: string, workspaceRoot: string): string {
   }
   const rel = relative(workspaceRoot, absolute)
   if (rel === '') return '.'
-  const outside = rel.startsWith('..') || isAbsolute(rel)
+  // A leading `..` SEGMENT (or an absolute rel) means outside the workspace; guard against a false
+  // positive on an in-workspace path whose first component merely starts with dots (e.g. `..gen/x`).
+  const outside = rel === '..' || rel.startsWith(`..${sep}`) || isAbsolute(rel)
   return outside ? absolute : rel.split(sep).join('/')
 }