Configurable allowlist of URL schemes for autolinking

[ralf.ebert]

Use case or problem

Knowledge workers and developers use custom URL schemes like - zotero:, vscode:, and sometimes self-built schemes for jumping into context. The only form Obsidian renders as clickable in Source mode for those schemes is [label](custom:foo). Bare URLs and <custom:foo> autolinks are not clickable, while links with standard schemes like https:// are. The additional wrapper and the need to always think about a label adds considerable friction here.

Proposed solution

A core plug-in that allows to configure “Clickable URL schemes” accepting a list of scheme names (e.g. zotero, vscode, mycustomapp). For listed schemes, bare URLs should be autolinked both in source mode and reading view.

It should be done as opt-in to avoid surprising users whose notes contain something like foo:bar that aren’t URLs.

Current workaround (optional)

Related feature requests (optional)

Related: #3173, #8102.

[ralf.ebert]

In some cases using a file property might be workaround, here the auto-linking works properly:

Unsure if it would need explicit configuration or if Obsidian maybe could get the list of registered schemes from the system (on MacOS this seems to be possible). In any case, as URI’s do not always have the `://` thing, probably it would be good if it’s restricted to “things known to be protocol”. Like, `foo:bar` should only become a link if there’s an app installed that handles the `foo:` scheme or if the user explicitly configured that `foo:` should be treated as URI.