hive-c0re: split OpenAPI summary/description, move param docs to params

utoipa splits a handler's doc comment on the first blank `///` line:
everything before it becomes the OpenAPI `summary` (shown in Swagger
UI's collapsed endpoint-list row), everything after becomes the
`description` (only shown once that row is expanded). With no blank
line, the whole doc comment becomes the summary and the description is
empty — which is what every handler in hive-c0re/src/dashboard/ was
doing, so the all-endpoints list showed full multi-sentence prose next
to every route instead of a short one-liner.

For every `#[utoipa::path(...)]`-annotated handler across the 19 files
in that module:

- Inserted a blank `///` line after the first short sentence/clause so
  utoipa's split produces a real summary + description, where the doc
  comment had more to say. Left already-short single-clause docs alone
  (nothing to split).
- Where a query struct derives `IntoParams`, moved param prose that
  duplicated a field's own doc comment out of the handler doc (the
  field already documents itself in the generated spec), or added a
  field doc where the handler explained a param that had none.

No behavior changes — doc comments and `params()` description text
only. Verified `cargo build -p hive-c0re` (clean) and `nix fmt` (zero
changes) after.

Closes #2969

hive-c0re/src/dashboard/questions.rs

@@ -94,14 +94,14 @@ pub(super) async fn post_answer_question(
     with_cors(resp)
 }
 
-/// Resolve a pending operator question with a sentinel answer when
-/// the operator decides not to / can't answer. The asker harness
-/// receives a `QuestionAnswered` event with `answer = "[cancelled]"`
-/// so it can fall back on whatever default it had. Same code path as
-/// a real answer — just lets the operator close the loop instead of
-/// letting the question dangle forever.
 /// `POST /cancel-question/{id}` — resolve a pending question with the
 /// `[cancelled]` sentinel answer.
+///
+/// Used when the operator decides not to / can't answer. The asker
+/// harness receives a `QuestionAnswered` event with
+/// `answer = "[cancelled]"` so it can fall back on whatever default
+/// it had. Same code path as a real answer — just lets the operator
+/// close the loop instead of letting the question dangle forever.
 #[utoipa::path(
     post,
     path = "/api/cancel-question/{id}",