* docs(iot-hub): spec for ${item-link:uuid} markdown component
Design for a new markdown placeholder that renders an item card
(thumbnail + name + creator) inline in IoT Hub readmes and install
instructions, opening the linked item in a new tab.
* docs(iot-hub): correct branch name in item-link spec
* docs(iot-hub): implementation plan for ${item-link:uuid} markdown component
Step-by-step task plan covering the placeholder utility, the link card
component, module wiring, three integration sites (item readme, device
install instructions, solution install instructions), translations, and
manual visual QA.
* feat(iot-hub): add item-link placeholder utility for markdown
* feat(iot-hub): add TbIotHubItemLinkCardComponent for markdown item links
* refactor(iot-hub): remove impossible-state guards in item-link card
* feat(iot-hub): wrap item-link card in IotHubItemLinkModule
* feat(iot-hub): add item-link-unavailable translation key
* feat(iot-hub): render ${item-link} cards in item readme
* feat(iot-hub): render ${item-link} cards in device install instructions
* feat(iot-hub): render ${item-link} cards in solution install instructions
* fix(iot-hub): match item-link card thumbnail to search popup (99x56, contain)