[bdbarnett]

Builds the binding against LVGL 9.6 (release/v9.6 at d8a4e1d: 9.6.0 and 24 fixes since; there is no 9.6.1 tag yet). Draft: whether main moves to 9.6 is still open, and the measurements on boards are being gathered against 9.5.54 with the same firmware.

What changed:

• lv_conf.h uses 9.6's option names (LV_COLOR_FORMAT_DEFAULT, no LV_MEM_POOL_EXPAND_SIZE, the calendar names and the external ThorVG and LZ4 switches gone), so no deprecation #warning stops a -Werror build.
• Asserts: 9.6 makes LV_USE_ASSERT a master switch that is off by default, which would silently drop the NULL and malloc checks the ports' assert handlers report. It's set on here, with the same checks as before. LV_USE_CHECK_ARG, which 9.6 adds and enables by default, is set explicitly. Several of 9.5's asserts became these argument checks, which return quietly. On MicroPython a failed check also goes to the assert handler, so a bad argument still raises RuntimeError (the smoke test's set_tile_cnt(256)). CircuitPython's handler reboots into safe mode and CPython's halts, so there a failed check just returns.
• The ports and scripts read 9.6's headers from include/lvgl/ and fall back to the 9.5 paths. The opt-in TLSF pool switches on LV_USE_TLSF itself, because 9.6 derives it before our override applies.
• The generated C wraps LVGL's own LV_DEPRECATIONS_IGNORE_BEGIN, because the binding still binds 36 functions that 9.6 marks deprecated.
• The CPython jpegio decoder is synced from micropython-pydevices, whose decoder now includes lvgl_private.h rather than the private header that moved.
• The API baseline records 9.6's renames and additions as upstream changes. verify_bindings.sh allows the CircuitPython file to reach 60,000 lines, up from 52,000; it is 53,495.
• scripts/generate_font_bins.py runs LVGL's font generator from scripts/generators/built_in_font/, where 9.6 moved it. The two CJK fonts gain the eight glyphs 9.6 added.
• The CircuitPython Unix job applies micropython-pydevices' two qstr offset patches, at a pinned commit, on CircuitPython 11.0.0-alpha.2. With 9.6's names the coverage build's qstr pool is past the 64 KB that 2-byte offsets address, and the port already asks for 4.
• tools/lvgl_bench.py measures heap use and refresh time the same way on every interpreter, so two builds can be compared.

Python names that go away. LVGL renamed these and keeps the old names only as C macros, which the binding can't see:

9.5	9.6
lv.draw_sw_rgb565_swap	lv.draw_rgb565_swap
lv.draw_sw_rotate	lv.draw_rotate
lv.draw_sw_i1_*	lv.draw_i1_*
display.delete_event	display.remove_event
obj.is_valid	obj.is_in_widget_tree
observer.remove	observer.delete
subject.copy_string	subject.set_string

The API grows from 2,156 functions to 2,317. LVGL 9.6's private headers also add 164 *_internal helpers. All but one back a public function of the same name, so the binding leaves them out. That saves 17.7 KB on an ESP32-S3 and 15.3 KB on the GIGA.

Checked: regenerate_all.sh is deterministic. verify_bindings.sh passes, including MicroPython, CircuitPython and CPython namespace parity and a mypy-clean stub. The generator tests pass (112), and so do the CPython extension tests (30 passed, 2 skipped) and the smoke test (28 checks), which match 9.5.54.

Needs the micropython-pydevices change that fetches LVGL's include/ directory and moves the jpegio include.