Add quad_index, which draws an indexed quad list as two triangles per quad and closes an indexed line loop, from the game's own indices, and log the first such draw either way.

Vulkan has no quad or line-loop topology. Draws without indices were rewritten already; an indexed quad list went to the GPU with its indices under the triangle list topology, three at a time, joining corners of neighbouring quads, and an indexed loop lacked its closing line. Off by default and read at start; no log of Ocarina has shown such a draw so far, and the new line says when one comes. tests/index_rewrite_check.py checks the index lists.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

nx2navi.ini.example

@@ -147,6 +147,12 @@
 # full count of the same object (or what was counted, if that is more). The log says how often it happens either way
 # ("samples-passed reports so far missed draws", at the 1st, 10th, 100th...). Read at start.
 # oq_hold = 0
+# Indexed quads and line loops, 0 or 1. Default: off. Vulkan has no quad or line-loop topology: draws without indices
+# are rewritten already, and 1 does the same for indexed ones (two triangles per quad, a closing line for a loop), which
+# otherwise are drawn with the game's indices as triangles and an open line, joining corners of neighbouring quads.
+# The log names the first such draw either way ("an indexed quad list"); without that line the game has drawn none.
+# Read at start.
+# quad_index = 0
 # EXPERIMENT, 0 or 1. Default: off. The game asks the video card how much of an object would show behind what is
 # already drawn (an occlusion query) and leaves hidden objects out. With 1 it asks nothing and draws them all: more
 # draws in a frame, and no queries to issue or results to wait for and read back. Whether that gains or loses frames