Promote `exclude_from_history` from extensions

[Hinton]

Now that every platform implements exclude_from_history it would be nice if it could be promoted from platform specific extensions to Clipboard.

[complexspaces]

Hey there, thanks for the suggestion 👋.

I don't think my stance has changed much since I made this comment last year. iOS and Android will have a way of doing this but the incoming WASM backend will not, AFAIK.

I'll think about if WASM being tier 2 (#191) would allow this method to no-op, since its just a hint anyway 🤔

[Hinton]

Ah I did not consider wasm. Yea that's fair.

[complexspaces]

This is some surface-level web research I did:

• No way to copy and mark something as sensitive in JavaScript programmatically.
• Firefox appears to only mark things as sensitive in unclear cases (I struggled to follow the IPC logic), but its not set by default.
• Chromium only marks copied values from sensitive if they're coming from a private/incognito browser context.

[Hinton]

I've been tracking w3c/clipboard-apis#154 which is a proposal to add a option to specify the value being sensitive to the clipboard APIs. Unfortunately it seems to have stalled.