v0.3.0

chore(release): 0.3.0

Milestone grouping the two headline additions since 0.2.0:
- a new **mtop transport** (Alibaba gateway — AliExpress, reusable for Taobao/Tmall/
  Lazada/1688), with in-session seed auto-acquisition, stringified-layer pagination,
  mtop detail calls, and per-order receipts as self-contained HTML invoices;
- the **download planner** (chrome.alarms scheduler: recurring source→sink deliveries,
  catch-up on next start, tab-open + retries when not signed in).

AliExpress source minVersion → 0.3.0. CHANGELOG [Unreleased] rolled to [0.3.0].