Share and save custom layouts

[mxtmx]

Custom layouts can be shared as a short text code or a link, and saved under a name.

• Sharing: a code lists each view by name with its grid position, so it can be edited by hand. Paste a code or link into the Share or Save Layout dialog, or open the link, then press Apply. A code that names a view this dashboard doesn't have, or comes from a newer code format, is rejected with a message saying so.
• Saving: saved layouts are kept in the browser and appear in the layout list at the top of the page. Picking one loads it, and the list marks it as edited once it changes. Saving under an existing name replaces that entry. Each tab keeps track of its own layout.
• Limits: codes are capped at 64 views, 100 rows per view, a bottom edge at row 300 and 3600 grid cells in total, since views like the field redraw a canvas of their own size on every telemetry packet.

A view's name in a code comes from its ConfigurableView member, lowercased without _VIEW and underscores (HARDWARE_CONFIG_VIEW is hardwareconfig), so new views need no extra step and the open PRs that add views still build. Renaming a member breaks codes that use it.

layout-share-demo.mp4