v0.8.0b3

[0.8.0b3]

Added

• Product URL on replaceable parts. A part can now carry a link to where you buy
  it (e.g. an Amazon listing). When set, the part's name in the appliance detail page
  becomes a clickable link that opens the product page in a new tab, so reordering a
  worn or consumed part is one click away. (Fixes #118)

• Attach a file to a replaceable part. A part can now carry a single attached
  file (a receipt, spec sheet, or photo) alongside its product URL — upload it from
  the part's editor and open or remove it later, the same secure upload/storage path
  appliance documents already use.

• A linked task's "Consumable link" points straight at the part's product page.
  When a maintenance task is tied to a part that has a product URL, that link now
  opens the product page directly — in the panel's task detail and on the dashboard
  card's task row — instead of just naming the part.

Fixed

• Fixed a batch of bugs found during an in-depth code review (correctness,
  security, and reliability), plus internal maintainability cleanups.