clippy: fix all warnings across all binaries

- &PathBuf → &Path in memory-search.rs signatures
- Redundant field name in graph.rs struct init
- Add truncate(false) to lock file open
- Derive Default for Store instead of manual impl
- slice::from_ref instead of &[x.clone()]
- rsplit_once instead of split().last()
- str::repeat instead of iter::repeat().take().collect()
- is_none_or instead of map_or(true, ...)
- strip_prefix instead of manual slicing

Zero warnings on `cargo clippy`.

src/bin/memory-search.rs

@@ -10,7 +10,7 @@
 use std::collections::HashSet;
 use std::fs;
 use std::io::{self, Read, Write};
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use std::process::Command;
 
 fn main() {
@@ -138,7 +138,7 @@ fn extract_key_from_line(line: &str) -> Option<String> {
     }
 }
 
-fn load_or_create_cookie(dir: &PathBuf, session_id: &str) -> String {
+fn load_or_create_cookie(dir: &Path, session_id: &str) -> String {
     let path = dir.join(format!("cookie-{}", session_id));
     if path.exists() {
         fs::read_to_string(&path).unwrap_or_default().trim().to_string()
@@ -165,7 +165,7 @@ fn generate_cookie() -> String {
         .collect()
 }
 
-fn load_seen(dir: &PathBuf, session_id: &str) -> HashSet<String> {
+fn load_seen(dir: &Path, session_id: &str) -> HashSet<String> {
     let path = dir.join(format!("seen-{}", session_id));
     if path.exists() {
         fs::read_to_string(path)
@@ -178,7 +178,7 @@ fn load_seen(dir: &PathBuf, session_id: &str) -> HashSet<String> {
     }
 }
 
-fn mark_seen(dir: &PathBuf, session_id: &str, key: &str) {
+fn mark_seen(dir: &Path, session_id: &str, key: &str) {
     let path = dir.join(format!("seen-{}", session_id));
     if let Ok(mut f) = fs::OpenOptions::new().create(true).append(true).open(path) {
         writeln!(f, "{}", key).ok();

src/capnp_store.rs

@@ -49,7 +49,7 @@ impl StoreLock {
     fn acquire() -> Result<Self, String> {
         let path = lock_path();
         let file = fs::OpenOptions::new()
-            .create(true).write(true).open(&path)
+            .create(true).truncate(false).write(true).open(&path)
             .map_err(|e| format!("open lock {}: {}", path.display(), e))?;
 
         // Blocking exclusive lock
@@ -268,7 +268,7 @@ pub struct GapRecord {
 }
 
 // The full in-memory store
-#[derive(Serialize, Deserialize)]
+#[derive(Default, Serialize, Deserialize)]
 pub struct Store {
     pub nodes: HashMap<String, Node>,          // key → latest node
     #[serde(skip)]
@@ -279,18 +279,6 @@ pub struct Store {
     pub params: Params,
 }
 
-impl Default for Store {
-    fn default() -> Self {
-        Store {
-            nodes: HashMap::new(),
-            uuid_to_key: HashMap::new(),
-            relations: Vec::new(),
-            retrieval_log: Vec::new(),
-            gaps: Vec::new(),
-            params: Params::default(),
-        }
-    }
-}
 
 impl Store {
     /// Load store: try state.json cache first, rebuild from capnp logs if stale
@@ -498,7 +486,7 @@ impl Store {
 
     /// Add a relation (appends to log + updates cache)
     pub fn add_relation(&mut self, rel: Relation) -> Result<(), String> {
-        self.append_relations(&[rel.clone()])?;
+        self.append_relations(std::slice::from_ref(&rel))?;
         self.relations.push(rel);
         Ok(())
     }
@@ -1036,7 +1024,7 @@ impl Store {
         let mut output = String::new();
         for node in &sections {
             if node.key.contains('#') {
-                let section_id = node.key.split('#').last().unwrap_or("");
+                let section_id = node.key.rsplit_once('#').map_or("", |(_, s)| s);
 
                 let links: Vec<_> = self.relations.iter()
                     .filter(|r| r.source_key == node.key && !r.deleted

src/graph.rs

@@ -371,7 +371,7 @@ impl Graph {
             same_community,
             delta_cc_source: cc_after_source - cc_before_source,
             delta_cc_target: cc_after_target - cc_before_target,
-            delta_gini: delta_gini,
+            delta_gini,
             assessment,
         }
     }

src/main.rs

@@ -44,7 +44,7 @@ fn find_current_transcript() -> Option<String> {
                     if p.extension().map(|x| x == "jsonl").unwrap_or(false) {
                         if let Ok(meta) = p.metadata() {
                             if let Ok(mtime) = meta.modified() {
-                                if newest.as_ref().map_or(true, |(t, _)| mtime > *t) {
+                                if newest.as_ref().is_none_or(|(t, _)| mtime > *t) {
                                     newest = Some((mtime, p));
                                 }
                             }
@@ -554,8 +554,8 @@ fn cmd_apply_agent(args: &[String]) -> Result<(), String> {
             let reason = link.get("reason").and_then(|v| v.as_str()).unwrap_or("");
 
             // Skip NOTE: targets (new topics, not existing nodes)
-            if target.starts_with("NOTE:") {
-                println!("  NOTE: {} — {}", &target[5..], reason);
+            if let Some(note) = target.strip_prefix("NOTE:") {
+                println!("  NOTE: {} — {}", note, reason);
                 continue;
             }
 
@@ -932,12 +932,12 @@ fn cmd_write(args: &[String]) -> Result<(), String> {
         let mut node = existing.clone();
         node.content = content;
         node.version += 1;
-        store.append_nodes(&[node.clone()])?;
+        store.append_nodes(std::slice::from_ref(&node))?;
         store.nodes.insert(key.clone(), node);
         println!("Updated '{}' (v{})", key, store.nodes[&key].version);
     } else {
         let node = capnp_store::Store::new_node(&key, &content);
-        store.append_nodes(&[node.clone()])?;
+        store.append_nodes(std::slice::from_ref(&node))?;
         store.uuid_to_key.insert(node.uuid, node.key.clone());
         store.nodes.insert(key.clone(), node);
         println!("Created '{}'", key);

src/neuro.rs

@@ -275,7 +275,7 @@ fn format_health_section(store: &Store, graph: &Graph) -> String {
     for (i, &count) in buckets.iter().enumerate() {
         let lo = i as f32 / 10.0;
         let hi = (i + 1) as f32 / 10.0;
-        let bar: String = std::iter::repeat('█').take((count as usize) / 10).collect();
+        let bar = "█".repeat((count as usize) / 10);
         out.push_str(&format!("  {:.1}-{:.1}: {:4} {}\n", lo, hi, count, bar));
     }