Kata editing permission is not thoroughly documented and UI is not consistent

[Bubbler-4]

Describe the bug

At 4000 honor, a user is supposed to get a power to contribute to others' katas. For approved katas though, the permission seems to vary from one kata to another. Also, a kata is sometimes editable even when it doesn't show "edit kata" button in the UI.

To Reproduce

Steps to reproduce the behavior:

1. Take an account with barely above 4K honor
2. Solve a kata, such as 6kyu Squares in a Rectangle or 6kyu String Character Frequency
3. Move to description or discussion page. "Edit kata" button is not there, for both of them.
4. Manually move into the editor page at /kata/(kata_title)/edit/(language_name)
5. For the first one, I get a simple error message "You do not have permissions to view this page". On the other hand, I could successfully edit the second and even republish.

Notably, both katas have Haskell versions as translations with <10 solves, and ~300 solves as whole kata. Also, both authors are active (last seen Feb 2019). The only difference is that the first hasn't got any issues yet. I remember that a kata is unlocked to community when it has a dangling issue for a week - is it still correct?

For the UI, my rough guess is that "Edit kata" gets hidden if the kata has "allow contributor" disabled, and it doesn't check for the "unlocked" status. Looking at this one, it already has "allow contributor" enabled but still doesn't show the "edit kata" button.

Contexts

• OS: Windows 8.1
• Browser: Chrome
• Browser Version: 71.0.3578.98

[LesnyRumcajs]

I can confirm this also happens on:

* OS: Linux Fedora 29
* Browser: Firefox
* Browser Version: 64.0.2 (64-bit)

[kazk]

I just looked at the code. For approved kata, "Edit Kata" is shown to authors and users with enough honor to approve kata (6000). This doesn't make any sense :(

I'll change this to show if you have enough honor to coauthor (4000).

EDIT: For approved kata, there's more conditions. See #1723 (comment)

[Bubbler-4]

@kazk Good, I can see the UI part is fixed. Can you confirm this part in the OP?

I remember that a kata is unlocked to community when it has a dangling issue for a week - is it still correct?

[kazk]

Yeah, I deployed that fix like 30 minutes ago.

For "dangling issue for a week", I'm still looking. I don't think I touched it since I inherited so it should be the same as before.

[kazk]

@Bubbler-4 For approved kata, you can edit if

1. You authored it
2. You coauthored it in the past
3. You have enough honor points to be a coauthor and there's unresolved issue/suggestion for over a week

So unresolved issue/suggestion is needed in order to become a new coauthor. For beta kata, this restriction doesn't apply.

I'll add this to the documentation.

[kazk]

Added to the bottom of Privileges