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/lifecycle_ops.rs

@@ -60,7 +60,9 @@ pub(super) async fn post_rebuild(
 }
 
 /// `POST /api/kill/{name}?graceful=1` — stop `name`, hard by default or
-/// gracefully (quiesce → drain → stop) when `graceful=1`.
+/// gracefully when `graceful=1`.
+///
+/// Graceful mode: quiesce → drain → stop.
 #[utoipa::path(
     post,
     path = "/api/kill/{name}",
@@ -120,7 +122,9 @@ pub(super) async fn post_kill(
 }
 
 /// `POST /api/restart/{name}?graceful=1` — restart `name`, hard by default
-/// or gracefully (quiesce → drain → restart) when `graceful=1`.
+/// or gracefully when `graceful=1`.
+///
+/// Graceful mode: quiesce → drain → restart.
 #[utoipa::path(
     post,
     path = "/api/restart/{name}",
@@ -423,9 +427,10 @@ pub(super) struct DestroyForm {
     purge: Option<String>,
 }
 
-/// `POST /api/destroy/{name}` — destroy `name`'s container. Form field
-/// `purge` (any non-empty value, e.g. `"on"`) also wipes the retained
-/// state dir instead of leaving a tombstone.
+/// `POST /api/destroy/{name}` — destroy `name`'s container.
+///
+/// Form field `purge` (any non-empty value, e.g. `"on"`) also wipes the
+/// retained state dir instead of leaving a tombstone.
 #[utoipa::path(
     post,
     path = "/api/destroy/{name}",