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/approvals.rs

@@ -251,9 +251,11 @@ impl Approvals {
     /// kind / agent / sha. Errors if the approval isn't pending — once
     /// it's approved/denied/failed/cancelled, the resolution is final.
     pub fn mark_cancelled(&self, id: i64, canceller: &str) -> Result<Approval> {
-        let mut conn = self.conn.lock().unwrap();
-        let tx = conn.transaction()?;
-        let row: Option<(
+        // Row-shape alias for the SELECT below so we don't trip
+        // clippy::type_complexity. Order matches the SELECT projection:
+        // agent, kind, commit_ref, requested_at, status, fetched_sha,
+        // description.
+        type CancelLookupRow = (
             String,
             String,
             String,
@@ -261,7 +263,10 @@ impl Approvals {
             String,
             Option<String>,
             Option<String>,
-        )> = tx
+        );
+        let mut conn = self.conn.lock().unwrap();
+        let tx = conn.transaction()?;
+        let row: Option<CancelLookupRow> = tx
             .query_row(
                 "SELECT agent, kind, commit_ref, requested_at, status, fetched_sha, description
                    FROM approvals WHERE id = ?1",
@@ -326,9 +331,7 @@ impl Approvals {
 /// bad row used to make `pending()` / `recent_resolved()` error out
 /// wholesale — the dashboard then rendered an empty approvals queue
 /// (issue #160, an unhandled `init_config` kind poisoning every read).
-fn collect_lenient(
-    rows: impl Iterator<Item = rusqlite::Result<Approval>>,
-) -> Vec<Approval> {
+fn collect_lenient(rows: impl Iterator<Item = rusqlite::Result<Approval>>) -> Vec<Approval> {
     rows.filter_map(|r| match r {
         Ok(a) => Some(a),
         Err(e) => {
@@ -467,7 +470,12 @@ mod tests {
         // status + a "cancelled by <who>" note.
         let (_dir, _path, db) = open_temp();
         let id = db
-            .submit_kind("bitburner", ApprovalKind::ApplyCommit, "cafef00d", Some("test"))
+            .submit_kind(
+                "bitburner",
+                ApprovalKind::ApplyCommit,
+                "cafef00d",
+                Some("test"),
+            )
             .unwrap();
         let row = db.mark_cancelled(id, "manager").expect("cancel");
         assert_eq!(row.id, id);