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/health.rs

@@ -49,12 +49,13 @@ struct ReadyBody {
     warnings: Vec<ServerWarning>,
 }
 
-/// `GET /health/ready` — readiness. `200` with `{"status":"ok", "warnings":
-/// [...]}` unless a `crit`-level warning is currently set in
-/// [`crate::warnings::snapshot`], in which case `503` with
-/// `{"status":"degraded", ...}`. `warnings` always carries the full
-/// current list (including `warn`-level entries not affecting the
-/// status) so a poller gets detail either way.
+/// `GET /health/ready` — readiness.
+///
+/// `200` with `{"status":"ok", "warnings": [...]}` unless a `crit`-level
+/// warning is currently set in [`crate::warnings::snapshot`], in which
+/// case `503` with `{"status":"degraded", ...}`. `warnings` always
+/// carries the full current list (including `warn`-level entries not
+/// affecting the status) so a poller gets detail either way.
 #[utoipa::path(
     get,
     path = "/health/ready",