[thorwhalen]

Refs #46 (does not close it: the warning could not be reproduced; the issue stays open for the reporter's environment).

• has_module: when find_spec raises (an imported module with __spec__ = None), a module present in sys.modules counts as present instead of "missing". Hypothesis fix.
• The yt-dlp-ejs message now names the interpreter it looked in, so the next occurrence is diagnosable (yt-dlp running from another interpreter, or scripts supplied via remote_components, are the likelier causes).

Adversarial review (Opus): safe to merge; hypothesis only weakly plausible (so the issue stays open); cannot hide a real missing-module warning (a None sys.modules entry still reads as missing); tests meaningful. Applied the two nits (message punctuation, docstring accuracy).