Which preset library a shot uses

Highest precedence first:

1. --preset-file <path> — one preset, parsed from that file.
2. --presets <dir> — every *.toml in that directory.
3. RLX_PRESET_DIR — the environment override (ADR-0014).
4. The per-user preset directory (%APPDATA%\Ritmolux\presets on Windows; see Expression language).
5. The presets compiled into the binary.

The [source] label printed after every capture names the winner, so a PNG’s provenance is never a guess. The two flags are errors when they come up empty — a missing file, unparseable TOML, or a directory with no valid presets exits non-zero rather than quietly capturing some other library. Levels 3–5 degrade downward instead, exactly as the app does.

shot resolves levels 3 and 4 through the same standalone library function the app calls, so the two can never disagree about which folder your edit landed in.