docs(#2671): trim per-verb arg help (diff, list, lint, pr-merge)

Continue trimming clap arg help to user-relevant info: drop the
token-bounded-paging rationale (list --page), the why-it's-required
note (lint no-reviewer), the `Forgejo Do:`/`force_merge` API internals
(pr-merge), and tighten diff --full. pr-status was already clean.

hive-forge/src/verbs/lint.rs

@@ -109,10 +109,8 @@ struct NoReviewerArgs {
     /// Filter by PR state.
     #[arg(long, value_enum, default_value_t = State::Open)]
     state: State,
-    /// Reviewer login to look for (matches `@<reviewer>` in PR body or
-    /// any comment). Required — defaulting to a specific name would
-    /// bake one deployment's reviewer convention into the binary
-    /// (flagged in review).
+    /// Reviewer login to look for (matches `@<reviewer>` in the PR body
+    /// or any comment).
     #[arg(long)]
     reviewer: String,
 }