clippy: fix lints that crane's cargoClippy properly enforces (#538)

The naersk → crane swap in the parent commit flips clippy from
silently passing to actually failing on `-D warnings` (naersk's
`mode = "clippy"` mangled the `--` separator so the deny never took
effect). This commit clears the surfaced lints so the workspace
builds clean under the new enforcement — every fix is mechanical and
preserves behaviour. Tests still pass (160 across the workspace).

Auto-fixes via `cargo clippy --fix`:
- `doc_markdown` (19 sites): bare identifiers in doc comments
  wrapped in backticks
- `format_in_format_args`, `explicit_into_iter_loop`,
  `redundant_closure_for_method_calls`, `useless_conversion`, and
  a few more — mechanical rewrites of the kind cargo can apply
  safely.

Hand-fixed:
- `match_same_arms` (forge_notify::is_atx_heading): two arms returning
  `true` collapsed into a single `matches!` pattern.
- `cast_sign_loss` + `format_push_string` (mcp.rs status formatter):
  guarded `i64 → u64` through `u64::try_from(…).unwrap_or(0)` (status
  timestamps are always positive in practice; clamp the skew edge to
  0) and swapped `out.push_str(&format!(…))` for `write!` into the
  buffer with an infallible-writer `let _ =`.
- `doc_lazy_continuation` in turn.rs + manager_server.rs + sh4re/lib.rs:
  doc paragraphs that the markdown parser was treating as list-item
  continuations got either a separating blank line or a `/`-for-`+`
  word swap so the parser stops seeing a list.
- `unused_async` (manager_server::handle_request_schedule_prompt):
  function has no `.await`; dropped the `async` and its `.await` call
  site.
- `needless_pass_by_value` (scheduled_prompts::submit): take
  `&NewSchedule` instead of moving the struct in; updated two prod
  callers and eight test sites to pass references.
- `type_complexity` (approvals::mark_cancelled): hoisted the
  7-tuple SELECT row shape into a `type CancelLookupRow = (…);` alias.

Allow-with-reason for intentional patterns:
- `option_option` (6 sites across dashboard / scheduled_prompts /
  manager_server): `Option<Option<T>>` carries three-state PATCH
  semantics (missing key = leave alone, `Some(None)` = clear,
  `Some(Some(v))` = set). Collapsing to `Option<T>` loses the
  "clear" state.
- `dead_code` (rebuild_queue::QueueKind::Destroy /
  QueueSource::CrashRecover; topology::parent_of / default_seed):
  wire-shape variants + API surfaces kept for the upcoming features
  (#361 follow-ups, future `Destroy` queue routing, crash-recovery
  path). Allowed at the variant / function level with the rationale
  in `reason = "…"`.
- `too_many_lines` on three specific call-sites: a 117-line
  exhaustive-variant test (dashboard_events::kind_tag_matches_…),
  the meta-flake string template renderer
  (meta::render_flake_with_lookup), and the notification poll loop
  (forge_notify::poll_once) — splitting any of them would just hide
  the contiguous shape they exist to keep visible.

`nix flake check` formatting target is still broken on main itself
(pre-existing nixfmt drift across ~28 files unrelated to this PR);
left alone here so the scope stays "crane port + lints the port
exposed" and the operator's review doesn't have to triage drive-by
nixfmt churn.

hive-c0re/src/actions.rs

@@ -151,21 +151,18 @@ async fn run_approval_schedule_prompt(
     approval: hive_sh4re::Approval,
 ) -> Result<()> {
     let result: Result<()> = async {
-        let payload: hive_sh4re::SchedulePromptPayload =
-            serde_json::from_str(&approval.commit_ref)
-                .context("decode SchedulePromptPayload from approval.commit_ref")?;
+        let payload: hive_sh4re::SchedulePromptPayload = serde_json::from_str(&approval.commit_ref)
+            .context("decode SchedulePromptPayload from approval.commit_ref")?;
         coord
             .scheduled_prompts
-            .submit(crate::scheduled_prompts::NewSchedule {
+            .submit(&crate::scheduled_prompts::NewSchedule {
                 owner: approval.agent.clone(),
                 targets: payload.targets,
                 body: payload.body,
                 first_fire_at_unix: payload.first_fire_at_unix,
                 interval_seconds: payload.interval_seconds,
                 description: payload.description,
-                source: crate::scheduled_prompts::ScheduleSource::Approval {
-                    id: approval.id,
-                },
+                source: crate::scheduled_prompts::ScheduleSource::Approval { id: approval.id },
             })
             .map(|_| ())
             .context("insert scheduled prompt")
@@ -290,9 +287,10 @@ async fn forge_after_first_spawn(coord: &Arc<Coordinator>, agent: &str) {
         tracing::warn!(%agent, error = ?e, "forge: ensure_config_repo after first spawn failed");
     }
     if let Some(core_token) = crate::forge::core_token()
-        && let Err(e) = crate::forge::meta_read_access(agent, &core_token).await {
-            tracing::warn!(%agent, error = ?e, "forge: meta_read_access after first spawn failed");
-        }
+        && let Err(e) = crate::forge::meta_read_access(agent, &core_token).await
+    {
+        tracing::warn!(%agent, error = ?e, "forge: meta_read_access after first spawn failed");
+    }
     if let Err(e) = crate::forge::ensure_meta_remote(agent).await {
         tracing::warn!(%agent, error = ?e, "forge: ensure_meta_remote after first spawn failed");
     }
@@ -466,7 +464,7 @@ async fn run_apply_commit(
                 Err(anyhow::anyhow!("read applied/main: {e:#}")),
                 None,
                 is_first_spawn,
-            )
+            );
         }
     };
 
@@ -521,8 +519,7 @@ async fn run_apply_commit(
             Ok(a) => a,
             Err(e) => {
                 let _ =
-                    lifecycle::git_update_ref(applied_dir, "refs/heads/main", &prev_main_sha)
-                        .await;
+                    lifecycle::git_update_ref(applied_dir, "refs/heads/main", &prev_main_sha).await;
                 let _ = lifecycle::git_read_tree_reset(applied_dir, "refs/heads/main").await;
                 return (
                     Err(anyhow::anyhow!("agents_for_meta_listing_with: {e:#}")),
@@ -540,8 +537,7 @@ async fn run_apply_commit(
         )
         .await
         {
-            let _ =
-                lifecycle::git_update_ref(applied_dir, "refs/heads/main", &prev_main_sha).await;
+            let _ = lifecycle::git_update_ref(applied_dir, "refs/heads/main", &prev_main_sha).await;
             let _ = lifecycle::git_read_tree_reset(applied_dir, "refs/heads/main").await;
             return (
                 Err(anyhow::anyhow!("meta sync_agents for first spawn: {e:#}")),