Inconsistent opening wording for options in the post flag dialog box

[trichoplax]

Describe the bug When flagging a post, there are several options to choose from. Some start with "it's", some "is", and some have no introductory word before the content. This inconsistency doesn't break anything but looks jarring.

To Reproduce Steps to reproduce the behavior:

1. Flag a post.
2. Notice the inconsistency between "it's spam", "is a duplicate", and "generated by AI"

Expected behavior Ideally all the options would have a consistent approach. My personal preference would be to drop the leading "it's" and "is", and simply have "spam", "duplicate", and "generated by AI".

[cellio]

Making the change is easy (it's a config file). Making it not create near-duplicate entries might involve direct DB wrangling because seeds are additive.