fix(lsp): read self.context_state instead of stale local variable in _context_get_or_load

_context_get_or_load captures self.context_state into a local variable
`state` at the top of the method. After _create_lsp_context() or
_ensure_context_for_document() successfully updates self.context_state
to ContextLoaded, the final check on line 1077 reads the stale local
`state` (still NoContext) instead of self.context_state.

This causes the method to always raise RuntimeError("Context failed to
load") on the first didOpen, even when context loading succeeds. The
LSP logs "Loaded SQLMesh Context" then immediately crashes. In VS Code,
this puts the client into a permanent "Client got disposed and can't be
restarted" state.

Signed-off-by: jthurlburt <jthurlburt818@gmail.com>

Author: jthurlburt

sqlmesh/lsp/main.py

@@ -1074,8 +1074,8 @@ def _context_get_or_load(self, document_uri: t.Optional[URI] = None) -> LSPConte
                     loaded_sqlmesh_message(self.server)
             else:
                 self._ensure_context_for_document(document_uri)
-        if isinstance(state, ContextLoaded):
-            return state.lsp_context
+        if isinstance(self.context_state, ContextLoaded):
+            return self.context_state.lsp_context
         raise RuntimeError("Context failed to load")
 
     def _ensure_context_for_document(