fix(#999): resolve all clippy warnings across the workspace

All crates now pass `cargo clippy --workspace -- -D warnings` cleanly.

Fixes span six crates (hive-sh4re, hive-ag3nt, hive-c0re, hive-forge,
hive-priv, hive-matrix-mcp was already clean):

- doc_markdown: wrap snake_case, type names, constants in backticks
- collapsible_if / collapsible_match: fold nested ifs into let-chains
- duration_suboptimal_units: Duration::from_secs(N) → from_mins/from_hours
- implicit_hasher: allow on HashMap-param fns where generalization is risky
- items_after_statements: hoist use to function tops
- map(f).unwrap_or(x) → map_or(x, f); map(f).unwrap_or_else(g) → map_or_else
- is_ok_and / is_none_or in place of map().unwrap_or(bool)
- needless_continue: {} instead of continue in loop match arms
- match_same_arms: Ok(None) | Err(_) merged
- format_push_str: write!() instead of push_str(&format!())
- while let replaces loop { let Some(..) = x else { break } }
- struct_excessive_bools / dead_code: allow on purpose-built structs
- too_many_lines / too_many_arguments: allow where refactor not worth it
- unused_async: remove async from poll_once in bash_runner
- needless_borrow: fix &repo deref in hive-forge comments verb
- cast_possible_truncation: allow u64→usize in fetch_tail

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

hive-c0re/src/auto_update.rs

@@ -209,16 +209,16 @@ pub async fn ensure_manager(coord: &Arc<Coordinator>) -> Result<()> {
 /// Sort `names` in-place so parents precede their children in the topology.
 /// Uses BFS from root agents (depth 0). Agents absent from `topo` sort last,
 /// alphabetically within their tier. Stable within each depth tier.
-pub fn topology_sort(names: &mut Vec<String>, topo: &std::collections::BTreeMap<String, Option<String>>) {
+pub fn topology_sort(names: &mut [String], topo: &std::collections::BTreeMap<String, Option<String>>) {
     use std::collections::{HashMap, VecDeque};
     // Build depth map using owned clones so the borrow on `names` is released
     // before the sort_by mutable borrow.
-    let name_set: Vec<String> = names.clone();
+    let name_set: Vec<String> = names.to_vec();
     let mut depth: HashMap<String, usize> = HashMap::new();
     let mut queue: VecDeque<String> = VecDeque::new();
     // Seed roots: entries with no parent, or names not present in topo at all.
     for name in &name_set {
-        if topo.get(name).map_or(true, |p| p.is_none()) {
+        if topo.get(name).is_none_or(Option::is_none) {
             depth.insert(name.clone(), 0);
             queue.push_back(name.clone());
         }