Login streak board

A language-learning app shows a streak board: for each learner, how many days in a row they have practised. Work it out from raw login events recorded with different timezone offsets.

Each event is a string "name YYYY-MM-DDTHH:MM+HH:MM" or "name YYYY-MM-DDTHH:MM-HH:MM": the learner's name, the local date and time of the login, and the offset of that local time from UTC (so 2024-03-01T20:00-05:00 happened at 01:00 UTC on March 2).

The board uses a single reporting timezone tz (a UTC offset such as "+09:00"). A learner is active on a calendar day if at least one of their logins falls on that day *as seen in the reporting timezone* (convert the instant to tz; do not use the date written in the event). Several logins on one day count as one active day. Days are real calendar days, so February has 29 days in 2024 and year ends roll over normally.

A streak is a maximal run of consecutive active days. For each learner report:

• longest: the length of their longest streak;
• current: the length of the streak that ends on their most recent active day, but only if that day is today or the day before it (the learner can still extend it today); otherwise 0.

today is a date, "YYYY-MM-DD", in the reporting timezone. Events on days after today are ignored as if they were not in the log, and a learner with no remaining events is not reported. Names are case-sensitive.

Input: events, a list of strings in the format above; today, a string; tz, a string "+HH:MM" or "-HH:MM".

Output: a list of strings "name longest current", one per reported learner, ordered by longest descending, then current descending, then name ascending lexicographically.