v0.0.19: contact list + message history (local, persistent)

Storage:
- contacts sled tree: auto-tracked on send/receive
  - fingerprint, alias, first_seen, last_seen, message_count
- history sled tree: all messages stored locally
  - key: hist:<peer_fp>:<timestamp>:<uuid> for ordered scan
  - sender, text, is_self, timestamp

TUI commands:
- /contacts or /c — list all contacts (sorted by most recent)
  Shows alias, fingerprint, message count
- /history or /h — show last 50 messages with current peer
- /h <fingerprint> — show history with specific peer

Auto-tracking:
- On send: touch_contact + store_message (is_self=true)
- On receive: touch_contact + store_message (is_self=false)
- Both KeyExchange and Message variants tracked

Backup: contacts + history included in export_all (encrypted backup).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

warzone/crates/warzone-client/src/storage.rs

@@ -8,6 +8,8 @@ use x25519_dalek::StaticSecret;
 pub struct LocalDb {
     sessions: sled::Tree,
     pre_keys: sled::Tree,
+    contacts: sled::Tree,
+    history: sled::Tree,
     _db: sled::Db,
 }
 
@@ -35,9 +37,13 @@ impl LocalDb {
         };
         let sessions = db.open_tree("sessions")?;
         let pre_keys = db.open_tree("pre_keys")?;
+        let contacts = db.open_tree("contacts")?;
+        let history = db.open_tree("history")?;
         Ok(LocalDb {
             sessions,
             pre_keys,
+            contacts,
+            history,
             _db: db,
         })
     }
@@ -109,6 +115,90 @@ impl LocalDb {
         }
     }
 
+    // ── Contacts ──
+
+    /// Add or update a contact. Called on send/receive.
+    pub fn touch_contact(&self, fingerprint: &str, alias: Option<&str>) -> Result<()> {
+        let fp = fingerprint.chars().filter(|c| c.is_ascii_hexdigit()).collect::<String>().to_lowercase();
+        let now = chrono::Utc::now().timestamp();
+
+        let mut record = match self.contacts.get(fp.as_bytes())? {
+            Some(data) => serde_json::from_slice::<serde_json::Value>(&data).unwrap_or_default(),
+            None => serde_json::json!({}),
+        };
+        let obj = record.as_object_mut().unwrap();
+        obj.insert("fingerprint".into(), serde_json::json!(fp));
+        obj.insert("last_seen".into(), serde_json::json!(now));
+        if let Some(a) = alias {
+            obj.insert("alias".into(), serde_json::json!(a));
+        }
+        if !obj.contains_key("first_seen") {
+            obj.insert("first_seen".into(), serde_json::json!(now));
+        }
+        let count = obj.get("message_count").and_then(|v| v.as_u64()).unwrap_or(0);
+        obj.insert("message_count".into(), serde_json::json!(count + 1));
+
+        self.contacts.insert(fp.as_bytes(), serde_json::to_vec(&record)?)?;
+        Ok(())
+    }
+
+    /// Get all contacts sorted by last_seen (most recent first).
+    pub fn list_contacts(&self) -> Result<Vec<serde_json::Value>> {
+        let mut contacts: Vec<serde_json::Value> = self.contacts.iter()
+            .filter_map(|item| {
+                item.ok().and_then(|(_, data)| serde_json::from_slice(&data).ok())
+            })
+            .collect();
+        contacts.sort_by(|a, b| {
+            let ta = a.get("last_seen").and_then(|v| v.as_i64()).unwrap_or(0);
+            let tb = b.get("last_seen").and_then(|v| v.as_i64()).unwrap_or(0);
+            tb.cmp(&ta)
+        });
+        Ok(contacts)
+    }
+
+    // ── Message History ──
+
+    /// Store a message in local history.
+    pub fn store_message(&self, peer_fp: &str, sender: &str, text: &str, is_self: bool) -> Result<()> {
+        let fp = peer_fp.chars().filter(|c| c.is_ascii_hexdigit()).collect::<String>().to_lowercase();
+        let now = chrono::Utc::now().timestamp();
+        let id = uuid::Uuid::new_v4().to_string();
+
+        let msg = serde_json::json!({
+            "id": id,
+            "peer": fp,
+            "sender": sender,
+            "text": text,
+            "is_self": is_self,
+            "timestamp": now,
+        });
+
+        // Key: hist:<peer_fp>:<timestamp>:<uuid> for ordered scan
+        let key = format!("hist:{}:{}:{}", fp, now, id);
+        self.history.insert(key.as_bytes(), serde_json::to_vec(&msg)?)?;
+        Ok(())
+    }
+
+    /// Get message history with a peer (most recent N messages).
+    pub fn get_history(&self, peer_fp: &str, limit: usize) -> Result<Vec<serde_json::Value>> {
+        let fp = peer_fp.chars().filter(|c| c.is_ascii_hexdigit()).collect::<String>().to_lowercase();
+        let prefix = format!("hist:{}:", fp);
+
+        let mut messages: Vec<serde_json::Value> = self.history
+            .scan_prefix(prefix.as_bytes())
+            .filter_map(|item| {
+                item.ok().and_then(|(_, data)| serde_json::from_slice(&data).ok())
+            })
+            .collect();
+
+        // Take last N
+        if messages.len() > limit {
+            messages = messages.split_off(messages.len() - limit);
+        }
+        Ok(messages)
+    }
+
     /// Export all data as JSON (for encrypted backup).
     pub fn export_all(&self) -> Result<serde_json::Value> {
         let mut sessions = serde_json::Map::new();