geochron: clock_format "12h" overflows the sidebar on 128x32 — the AM/PM suffix isn't measured

[ChuckBuilds]

Summary

Setting clock_format: "12h" makes geochron's sidebar clock run 3px past the right edge on a 128x32 panel. show_seconds already defaults to true, so flipping that one setting is enough to trigger it — no unusual configuration needed.

Reproduction

Plugin v1.0.4, LEDMatrix v3.3.0-4-g0730d952:

cd ~/LEDMatrix
python3 scripts/check_plugin.py -p geochron -d ~/LEDMatrix/plugin-repos \
  --golden-dir /tmp/nogolden -c '{"clock_format": "12h"}'

[FAIL]  128x32  geochron overflow bbox=(128, 1, 131, 21)
[PASS]  64x32 / 64x64 / 96x48 / 128x64 / 256x32 / 128x96 / 256x128

Isolation

config	128x32
default (24h, show_seconds: true)	pass
clock_format: "12h"	FAIL
clock_format: "12h", show_seconds: true (explicit)	FAIL
clock_format: "12h", show_seconds: false	pass
clock_format: "24h", show_seconds: true	pass
clock_format: "12h", show_digital_clock: false	pass
graticule_step_deg: 15	pass

So it is exactly 12h + seconds, and only at 128x32.

Cause

geochron_renderer.py:185-195:

def format_clock(dt, fmt="24h", show_seconds=True):
    if fmt == "12h":
        hour = dt.hour % 12 or 12
        ampm = "AM" if dt.hour < 12 else "PM"
        if show_seconds:
            return f"{hour}:{dt.minute:02d}:{dt.second:02d}{ampm}"
        return f"{hour}:{dt.minute:02d}{ampm}"
    if show_seconds:
        return f"{dt.hour:02d}:{dt.minute:02d}:{dt.second:02d}"
    return f"{dt.hour:02d}:{dt.minute:02d}"

23:47:52 is 8 characters; 11:47:52PM is 10. In wide_sidebar mode the rows are drawn from sidebar_x + 2 with no measurement against the sidebar width, so the two extra characters spill over the panel edge.

The surrounding code shows the author was already width-conscious about this sidebar:

# The sidebar is narrow (~32px), so labels like "UTC"/"LCL" and full
# ISO dates don't fit a 4px-wide pixel font. Row order conveys
# meaning instead: ...

and the featured-city row explicitly drops seconds to save space:

time_str = format_clock(featured_city["local_dt"], clock_format, False)

The main clock rows just didn't get the same treatment for the 12h case.

Suggested fix

Any of:

• Drop seconds automatically when clock_format == "12h" and the sidebar is narrow, the way the featured-city row already does.
• Use a single-letter suffix (11:47:52p) or drop the AM/PM marker when it doesn't fit — in a sidebar this narrow the meridiem is arguably the least valuable character.
• Measure the formatted row against L["sidebar_w"] and shrink or trim, so any future format change is caught by construction.

How it was found

A schema-driven sweep that renders each plugin once per enum value / boolean combination / numeric bound derived from its own config_schema. Across 13 plugins and ~100 config variants this and one already-reported 7-segment-clock case were the only failures, so the sweep is quiet enough to be worth running in CI.

Environment

256x64 rig, LEDMatrix v3.3.0-4-g0730d952, geochron 1.0.4.