v0.2.2 — timeline delete + README cookbook

[0.2.2] - 2026-05-16

Added

• dvr timeline delete <name> — delete a timeline by name. Supports --dry-run.
  Auto-promotes another timeline to "current" if the deleted one was active.
• README Cookbook — five copy-paste end-to-end recipes covering render,
  batch import per date, bulk tag, CSV-driven markers, and MCP-agent dispatch.

Tests

• 6 new unit tests covering timeline delete happy path, missing name, empty
  name, dry-run, current-timeline promotion, and last-timeline removal.
• 184 unit tests total (was 178).