feat: friend list, bot API, ETH addressing, deep links, docs overhaul

Tier 1 — New features:
- E2E encrypted friend list: server stores opaque blob (POST/GET /v1/friends),
  protocol-level encrypt/decrypt with HKDF-derived key, 4 tests
- Telegram Bot API compatibility: /bot/register, /bot/:token/getUpdates,
  sendMessage, getMe — TG-style Update objects with proper message mapping
- ETH address resolution: GET /v1/resolve/:address (0x.../alias/@.../fp),
  bidirectional ETH↔fp mapping stored on key registration
- Seed recovery: /seed command in TUI + web client
- URL deep links: /message/@alias, /message/0xABC, /group/#ops
- Group members with online status in GET /groups/:name/members

Tier 2 — UX polish:
- TUI: /friend, /friend <addr>, /unfriend <addr> with presence checking
- Web: friend commands, showGroupMembers() on group join
- Web: ETH address in header, clickable addresses (click→peer or copy)
- Bot: full WireMessage→TG Update mapping (encrypted base64, CallSignal,
  FileHeader, bot_message JSON)

Documentation:
- USAGE.md rewritten: complete user guide with all commands
- SERVER.md rewritten: full admin guide with all 50+ endpoints
- CLIENT.md rewritten: architecture, commands, keyboard, storage
- LLM_HELP.md created: 1083-word token-optimized reference for helper LLM

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

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

@@ -8,6 +8,8 @@ pub struct Database {
     pub tokens: sled::Tree,
     pub calls: sled::Tree,
     pub missed_calls: sled::Tree,
+    pub friends: sled::Tree,
+    pub eth_addresses: sled::Tree,
     _db: sled::Db,
 }
 
@@ -21,6 +23,8 @@ impl Database {
         let tokens = db.open_tree("tokens")?;
         let calls = db.open_tree("calls")?;
         let missed_calls = db.open_tree("missed_calls")?;
+        let friends = db.open_tree("friends")?;
+        let eth_addresses = db.open_tree("eth_addresses")?;
         Ok(Database {
             keys,
             messages,
@@ -29,6 +33,8 @@ impl Database {
             tokens,
             calls,
             missed_calls,
+            friends,
+            eth_addresses,
             _db: db,
         })
     }