PiFinder's internationalization (i18n) workflow — marking strings for translation, running the Babel extract/update/compile pipeline, adding or updating language translations, and filling in missing msgstr entries in .po files. Use whenever the user mentions translations, i18n, localization, locale, gettext, Babel, .po/.pot/.mo files, language support, or asks about adding/updating a language. Also use when reviewing a diff that touches user-visible UI strings and you need to check whether they're wrapped for translation.
Author and edit PiFinder's user-facing documentation in the project's house style. The published docs are reStructuredText (.rst) in docs/source/, built with Sphinx + the Read the Docs theme and hosted at pifinder.readthedocs.io. Use this skill whenever the user wants to write, add, update, or polish documentation — documenting a new feature, menu, screen, or setting in the user guide; creating a new doc page and wiring it into the toctree; or revising existing prose for clarity and voice — even if they never say "reStructuredText" or "Sphinx". Trigger on mentions of docs, documentation, user guide, quick start, build guide, readthedocs, .rst files, or "document this feature / write up how this works". Do NOT use for docs/ax CONTEXT.md glossaries or ADRs (use grill-with-docs for those), for Python docstrings / code comments, or for edits confined to the repo-root README.
Run the PiFinder app headlessly and drive it like a user — launch it with no pygame window or physical display, send keypad presses to navigate menus, capture the 128x128 screen as a PNG, read live state (plate solve, location, IMU, SQM), and stop it cleanly. Use this whenever you need to actually operate or observe the running PiFinder UI rather than just read its code: "launch/start/run PiFinder", "navigate to <menu/screen>", "take a screenshot of PiFinder", "press UP/DOWN/SQUARE", "what's on the PiFinder screen", "what is it solving / where is it pointing", "check the UI shows X", "reproduce this UI bug", "drive the PiFinder interface", or "stop/shut down PiFinder". Also use it to verify UI-affecting changes by running the app and looking at the screen.