Unlock seed once at startup, pass identity to all commands

- main.rs unlocks seed once, prompts passphrase once per app launch
- Identity passed as parameter to send, recv, register, chat
- No more redundant load_seed() calls (was prompting passphrase multiple times)
- info command uses pre-unlocked identity directly

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

warzone/crates/warzone-client/src/cli/info.rs

@@ -1,16 +1 @@
-use crate::keystore;
-
-pub fn run() -> anyhow::Result<()> {
-    let seed = keystore::load_seed()?;
-    let identity = seed.derive_identity();
-    let pub_id = identity.public_identity();
-
-    println!("Fingerprint: {}", pub_id.fingerprint);
-    println!("Signing key: {}", hex::encode(pub_id.signing.as_bytes()));
-    println!(
-        "Encryption key: {}",
-        hex::encode(pub_id.encryption.as_bytes())
-    );
-
-    Ok(())
-}
+// Info is now handled directly in main.rs with the pre-unlocked identity.