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/agent_server.rs

@@ -19,6 +19,7 @@ pub struct AgentSocket {
 }
 
 pub fn start(agent: &str, socket_path: &Path, coord: Arc<Coordinator>) -> Result<AgentSocket> {
+    use std::os::unix::fs::PermissionsExt as _;
     let agent = agent.to_owned();
     if let Some(parent) = socket_path.parent() {
         std::fs::create_dir_all(parent)
@@ -36,7 +37,6 @@ pub fn start(agent: &str, socket_path: &Path, coord: Arc<Coordinator>) -> Result
     // perms (0755) lock it out. 0666 lets the agent user connect;
     // the bind source dir is per-agent on host so blast radius is
     // unchanged.
-    use std::os::unix::fs::PermissionsExt as _;
     std::fs::set_permissions(socket_path, std::fs::Permissions::from_mode(0o666))
         .with_context(|| format!("chmod agent socket {}", socket_path.display()))?;
     tracing::info!(%agent, socket = %socket_path.display(), "agent socket listening");
@@ -95,7 +95,7 @@ async fn serve(stream: UnixStream, agent: String, coord: Arc<Coordinator>) -> Re
 /// cheap "is there anything pending?" check without blocking the
 /// turn for 30 seconds. To actually park, the caller passes a
 /// positive `wait_seconds`.
-pub(crate) const RECV_LONG_POLL_MAX: std::time::Duration = std::time::Duration::from_secs(180);
+pub(crate) const RECV_LONG_POLL_MAX: std::time::Duration = std::time::Duration::from_mins(3);
 
 /// Server-side hard cap on `Recv.max`. Bounds the size of a single
 /// round-trip so a confused caller can't drain the entire inbox in
@@ -357,6 +357,7 @@ async fn dispatch(req: &AgentRequest, agent: &str, coord: &Arc<Coordinator>) ->
 ///
 /// The manager is not exempt - grant `read_host_journal` in
 /// `meta/capabilities.json` to enable it for any agent including the manager.
+#[allow(clippy::too_many_arguments)]
 pub async fn dispatch_host_journal(
     agent: &str,
     unit: &Option<String>,
@@ -619,8 +620,7 @@ fn prepare_remind_storage(
 fn auto_reminder_path(agent: &str) -> String {
     let ts_ns = std::time::SystemTime::now()
         .duration_since(std::time::UNIX_EPOCH)
-        .map(|d| d.as_nanos())
-        .unwrap_or(0);
+        .map_or(0, |d| d.as_nanos());
     format!("/agents/{agent}/state/reminders/auto-{ts_ns}.md")
 }