Agent Skills: lc-log

Append today's practice session to data/progress.txt — the daily log that is the only source for the review plan. Writes the day's line in the log's own shape (the YYYYMMDD date, the bucket labels, the `|` session separators), carries forward the buckets still open from yesterday, and gets the annotations right, because `again` / `again!!!` / `ok` / `ok*` / `todo` are what the whole spaced-repetition schedule keys on. Use when asked to log practice, record what was solved today, update the progress file, or mark a problem as done or still shaky. Triggers - "log today's practice", "/lc-log 23 ok, 24 again!!", "record that I did 141 and 142 clean", "update progress".