api: Add "users/{user_id}/status" endpoint to fetch a single user's status.

[Vector73]

This PR adds "users/{user_id}/status" endpoint to the API documentation which fetches the status of a specified user.
It completes the work started in #19498.

**Screenshots and screen captures:**

Self-review checklist

• Self-reviewed the changes for clarity and maintainability
  (variable names, code reuse, readability, etc.).

Communicate decisions, questions, and potential concerns.

• Explains differences from previous plans (e.g., issue description).
• Highlights technical choices and bugs encountered.
• Calls out remaining decisions and concerns.
• Automated tests verify logic where appropriate.

Individual commits are ready for review (see commit discipline).

• Each commit is a coherent idea.
• Commit message(s) explain reasoning and motivation for changes.

Completed manual review and testing of the following:

• Visual appearance of the changes.
• Responsiveness and internationalization.
• Strings and tooltips.
• End-to-end functionality of buttons, interactions and flows.
• Corner cases, error conditions, and easily imagined bugs.

[laurynmm]

@Vector73 - Thanks for working on adding this endpoint and documentation!

I had a few notes on the endpoint implementation and on the API documentation. Let me know if you have any questions.

For your commit message in the second commit, the shared schema isn't an parameter so I was confused when I read it and looked at the changes. I'd more clearly explain what the shared schema is deduplicating in the yaml file...

Adds "/users/{user_id}/status" endpoint to the API documentation.

Creates a shared UserStatus schema that's used for the return value
of this new endpoint and for the user_status object returned by the
register queue endpoint.

[Vector73]

@laurynmm I have addressed the feedback above and uploaded the screenshots.

[laurynmm]

@Vector73 - Thanks for making those updates! I had a few more comments when reading through these changes again. Some of the issues here is that the original PR was out of date with some updates that have been made to the backend test classes.

One question I have is if we want to do anything about bot users as they would never have a status set. I haven't tested, but I assume that just returns an empty dict, which is probably fine...

[Vector73]

One question I have is if we want to do anything about bot users as they would never have a status set. I haven't tested, but I assume that just returns an empty dict, which is probably fine...

@laurynmm I tested that and it seems like for bots, "No user found" error is raised.

I have addressed the recent feedbacks.

[laurynmm]

@Vector73 - Looks good! Had one small comment. When that's updated, feel free to add the "integration review" label.

Also, just keep in mind that this python usage example will need to be updated for your changes in #30115 (depending on which one gets merged first).

[Vector73]

@zulipbot add "integration review"

[timabbott]

This is not an API change, just an API documentation change, and so does not belong here.

[timabbott]

Oh, it is, just the PR title is misleading :)

[timabbott]

Made a couple documentation tweaks, mainly to clarify the prior state for how to get these data. I also squashed the API documentation commit with the change adding the endpoint itself; it's generally an atomic change to add an API endpoint and document the new API endpoint. I also edited the PR description to fix #30059 (comment) and the commit message to fix #19079, which this new endpoint appears to resolve. Thanks @Vector73, @MSurfer20, and @laurynmm!

diff --git a/api_docs/changelog.md b/api_docs/changelog.md
index 9ee17a06ae..0955ccafe7 100644
--- a/api_docs/changelog.md
+++ b/api_docs/changelog.md
@@ -22,8 +22,8 @@ format used by the Zulip server that they are interacting with.
 
 **Feature level 262**:
 
-* [`GET /users/{user_id}/status`](/api/get-user-status): Added
-  a new endpoint to get a specified user's currently set
+* [`GET /users/{user_id}/status`](/api/get-user-status): Added a new
+  endpoint to fetch an individual user's currently set
   [status](/help/status-and-availability).
 
 **Feature level 261**
diff --git a/zerver/openapi/zulip.yaml b/zerver/openapi/zulip.yaml
index 2f636af455..619848b04b 100644
--- a/zerver/openapi/zulip.yaml
+++ b/zerver/openapi/zulip.yaml
@@ -8425,7 +8425,9 @@ paths:
         Get the [status](/help/status-and-availability) currently set by a
         user in the organization.
 
-        **Changes**: New in Zulip 9.0 (feature level 262).
+        **Changes**: New in Zulip 9.0 (feature level 262). Previously,
+        user statuses could only be fetched via the [`POST
+        /register`](/api/register-queue) endpoint.
       parameters:
         - $ref: "#/components/parameters/UserId"
       responses: