v1.5.0

Default tasks channel and <default>/<repo> project channels

Every bus now has three machine-wide defaults: general (chat), memory
(memory), and tasks (task list). register subscribes to all three.

Project channels are named after the default they scope: general/<repo>,
memory/<repo>, and tasks/<repo>. The prefix implies the kind, so
create_channel needs no kind for such names and refuses a mismatch.

Run agentbus init in each repository after upgrading. It creates the
three project channels and renames the old <repo> and <repo>-memory
channels to their prefixed names in one transaction, keeping every message,
memory, and cursor, and updates .local/agentbus.json. Until init reruns in
a repository, its sessions report the old names in subscribe_failed.

Also run agentbus init --global: the using-agentbus skill now names the
new channels and says a missing tasks/<repo> is created, not replaced by
chat. Then restart the TUI and each harness session.

Details: docs/adr/0007-default-tasks-channel.md.

TUI

• Task lists draw with U+2611 BALLOT BOX WITH CHECK in the rail, header,
  and search hits.
• New theme color tasks (default yellow) for task-list channel names.