v0.5.0

Stop the daemon before you upgrade and start it again after: the first open
of a cache moves its search index to the new format (#1). Then run
tg db vacuum once with the daemon stopped, to give the old index's space
back to the disk.

Added

• The cache no longer only grows. tg status shows each account's cache
  size, its WAL and the free space inside it, and tg status --sizes adds the
  size of each table. The daemon now deletes old API activity, expired
  rate-limit windows and old finished and failed sync jobs on a schedule;
  until now nothing pruned the first two, so they grew forever. How long it
  keeps each is set in config.json under cache.retention, and it never
  forgets a FLOOD_WAIT that is still running. The new
  tg db vacuum [--account] gives free space back to the disk and reports the
  bytes before and after. It works while the daemon runs on caches created by
  this version, and older caches need one run with the daemon stopped. Where
  SQLite is 3.43 or newer, the search index no longer keeps its own copy of
  every message's text, sender and chat, which makes a cache about 11–18%
  smaller; tg messages search results stay the same (#1).
• The daemon now keeps each account's contact list current. On each start
  and reconnect, and then every peer TTL (cache.staleness.peers, one week by
  default), it checks the list in the background with a hash, so an unchanged
  list costs one tiny reply and no contact writes. The first start after the
  upgrade fetches the full list once. Contacts added or removed on another
  device while it runs are applied when Telegram sends the update. The check
  covers who is a contact; names, usernames and phones still refresh with a
  changed list or tg contacts list --fresh (#8).

Changed

• tg sql queries that read the search index's own columns
  (message_search.text, sender, chat, files) now get NULL, and
  snippet() and highlight() over it no longer work, because the index
  keeps no copy of the text (#1). Join messages_cache by rowid for the text,
  as tg messages search does. Getting snippets back is #81.

Fixed

• With several accounts, the daemon ran one sync job at a time over all of
  them, so while one account's job waited out a FLOOD_WAIT (up to 5 minutes),
  every other account's sync stopped too, and with three or more busy
  accounts each one synced more slowly than alone. Each account now runs its
  own jobs, one at a time and 3 seconds apart as before, so one account's
  FLOOD_WAIT or slow page no longer holds the others, and tg daemon stop
  still ends every account's wait at once (#60).
• tg chats list --type community found no communities: Telegram lists a
  joined community apart from the other dialogs, and the daemon's dialog pass
  and tg chats list --fresh skipped it. Both now also cache every community
  the account joined, with its access hash, at the cost of one extra request.
  If that request fails, a FLOOD_WAIT included (it is not waited out), the
  dialogs are still cached and the next pass retries. A community has no
  messages of its own, so tg chats sync <community> no longer turns sync on
  for jobs that would fail: it exits with INVALID_ARGS and points at the
  community's linked chats, which sync as ordinary supergroups and channels.
  If an earlier version turned the community on, the error says that --auto
  turns it off and clears its failed jobs (#58).
• A contact removed on Telegram stayed marked as a contact for good, even
  after tg contacts list --fresh. The daemon and --fresh now unmark it and
  keep the user row (#8).