Clarify error messages by specifying WebFinger handle format

[obenland]

See https://wordpress.org/support/topic/make-follow-reply-button-form-easier-for-users/#post-18620743

Proposed changes:

• Update error messages in follow-me and remote-reply blocks to specify "WebFinger handle" instead of just "handle"
• Change invalidProfileError message from "valid profile URL or handle" to "valid profile URL or WebFinger handle"
• Applies to both src and build directories

Other information:

• Have you written new tests for your changes, if applicable?

This change addresses user feedback from WordPress.org support forum requesting clearer guidance about the expected input format.

Testing instructions:

• Go to a post with ActivityPub follow-me or remote-reply blocks enabled
• Try to enter an invalid handle format (e.g., just "mastodon.social")
• Verify the error message now shows "Please enter a valid profile URL or WebFinger handle" instead of the previous generic "handle" text
• Confirm this appears in both follow-me and remote-reply block error states

Changelog entry

• Automatically create a changelog entry from the details below.

Changelog Entry Details

Significance

• Patch
• Minor
• Major

Type

• Added - for new features
• Changed - for changes in existing functionality
• Deprecated - for soon-to-be removed features
• Removed - for now removed features
• Fixed - for any bug fixes
• Security - in case of vulnerabilities

Message

Clarify error messages by specifying WebFinger handle format for better user guidance

[Copilot]

Pull Request Overview

This PR improves user experience by clarifying error messages to specify "WebFinger handle" instead of the generic "handle" in ActivityPub blocks. The change addresses user feedback requesting clearer guidance about expected input formats.

• Updated error messages in follow-me and remote-reply blocks to be more specific
• Changed "Please enter a valid URL or handle" to "Please enter a valid profile URL or WebFinger handle"
• Applied changes consistently across both src and build directories

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
src/remote-reply/render.php	Updated invalidProfileError message to specify WebFinger handle format
src/follow-me/render.php	Updated invalidProfileError message to specify WebFinger handle format
build/remote-reply/render.php	Updated invalidProfileError message to specify WebFinger handle format
build/follow-me/render.php	Updated invalidProfileError message to specify WebFinger handle format

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[pfefferle]

Is "WebFinger" something a regular user understands? I would assume not!?

[obenland]

What would you suggest?

[pfefferle]

I actually like "handle"... or "email like" handle?

Have you tried to ask chatgpt?

[obenland]

Please enter a valid profile URL or use the @username@server format.

We do show @[email protected] as the placeholder in that input field.

[pfefferle]

Yes, we do!

[pfefferle]

Please also update the changelog text.