Aliases: human-readable names mapped to fingerprints

Server:
- POST /v1/alias/register — claim an alias (one per fingerprint)
- GET /v1/alias/resolve/:name — alias → fingerprint
- GET /v1/alias/whois/:fingerprint — fingerprint → alias (reverse)
- GET /v1/alias/list — list all aliases
- Bidirectional mapping in sled (a:name→fp, fp:fp→name)
- One alias per person, re-registering replaces old alias

Web client:
- /alias <name> — register your alias
- /aliases — list all registered aliases
- /info — now shows alias alongside fingerprint
- Peer input accepts @alias (resolved before sending)
- Received messages show @alias instead of fingerprint
- DM: paste @alias or fingerprint in peer input

CLI TUI:
- /alias <name> — register alias
- /aliases — list all aliases
- /peer @alias — resolves alias to fingerprint
- Alias resolution displayed in system messages

Addressing model:
- @manwe (local) → server resolves → fingerprint
- @manwe.b1.example.com (federated) → DNS resolve (Phase 3)
- Raw fingerprint → always works, no resolution

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

warzone/crates/warzone-server/src/db.rs

@@ -4,6 +4,7 @@ pub struct Database {
     pub keys: sled::Tree,
     pub messages: sled::Tree,
     pub groups: sled::Tree,
+    pub aliases: sled::Tree,
     _db: sled::Db,
 }
 
@@ -13,10 +14,12 @@ impl Database {
         let keys = db.open_tree("keys")?;
         let messages = db.open_tree("messages")?;
         let groups = db.open_tree("groups")?;
+        let aliases = db.open_tree("aliases")?;
         Ok(Database {
             keys,
             messages,
             groups,
+            aliases,
             _db: db,
         })
     }