hive-forge: fetch issue comments in one request; the endpoint has no paging

The forge's issue-comments endpoint takes no page or limit and always
returns the whole thread. #5055 wrapped view's fetch in all_pages, which
never saw a short page on a thread of 50+ comments and fetched the same
list 50 times: `issue view 3782` printed 3000 comments instead of 60.
`comments --limit K` sent K as a page size the forge ignored, so it
returned the whole thread.

view and pr status's last_comment now send one request. comments fetches
the thread once and cuts the --limit / --tail window client-side; the
X-Total-Count probe and the computed-page tail walk are gone, and the
count of comments outside the window is the length of the list.
--since is unchanged.

tests/comments_no_paging.rs runs the binary against a loopback mock
forge whose comments route ignores page and limit, as Forgejo's does.

hive-forge/src/verbs/view.rs

@@ -7,7 +7,7 @@ use forgejo_api::structs::{IssueGetCommentsQuery, StateType};
 
 use crate::client::{Client, index};
 use crate::notify;
-use crate::verbs::{all_pages, attachment_line, issue_reactions, reaction_summary, refuse_json};
+use crate::verbs::{attachment_line, issue_reactions, reaction_summary, refuse_json};
 
 #[derive(ClapArgs)]
 pub struct Args {
@@ -63,15 +63,12 @@ pub fn run(client: &Client, args: Args) -> Result<()> {
         println!("[reactions: {summary}]");
     }
     let idx = index(args.number)?;
-    let comments = all_pages(|page, size| {
-        let (_, batch) = client
-            .api()
-            .issue_get_comments(owner, name, idx, IssueGetCommentsQuery::default())
-            .page(page)
-            .page_size(size)
-            .send()?;
-        Ok(batch)
-    })?;
+    // One request: this endpoint takes no page or limit and returns the
+    // whole thread, so a paging loop would fetch it again on every page.
+    let (_, comments) = client
+        .api()
+        .issue_get_comments(owner, name, idx, IssueGetCommentsQuery::default())
+        .send()?;
     if !comments.is_empty() {
         println!();
         println!("---");