fix(dql): support IRI-ref at query start

[eileenaaa]

Description

This PR fixes a regression in DQL lexing where queries starting with an IRI-ref (names wrapped in < >, e.g., <caseNodeDel_xxx>) would fail with an Unexpected character: U+003C '<' error.

Root Cause:
In v25, the state function lexIdentifyMutationOrQuery was introduced to distinguish between mutations and queries. However, it lacked a case for the lsThan (<) character, causing the lexer to fail when a query block started with an IRI-ref instead of a standard name or keyword.

Changes:

• Updated lexIdentifyMutationOrQuery in dql/state.go to handle the lsThan (<) case.
• Ensures the lexer correctly calls lex.IRIRef and transitions to lexQuery.

Fixes #9666

Checklist

• The PR title follows the Conventional Commits syntax, leading with fix:, feat:, chore:, ci:, etc.
• Code compiles correctly and linting (via trunk) passes locally
• Tests added for new functionality, or regression tests for bug fixes added as applicable

[shiva-istari]

The test only asserts absence of errors but doesn't verify the IRI ref was actually parsed. A broken implementation that silently drops the token would still pass. Add a positive assertion that "user-query" was emitted as a token value (similar to TestNumberInLang), and drop the t.Log.

Suggested change

	t.Log(item.String())
	var foundIRI bool
	for it.Next() {
	item := it.Item()
	require.NotEqual(t, item.Typ, lex.ItemError, "Error: %v", item.String())
	if item.Val == "user-query" {
	foundIRI = true
	}
	}
	require.True(t, foundIRI, "expected IRI ref 'user-query' to be lexed")```