v0.0.21: TUI overhaul, WZP call infrastructure, security hardening, federation

TUI:
- Split 1,756-line app.rs monolith into 7 modules (types, draw, commands, input, file_transfer, network, mod)
- Message timestamps [HH:MM], scrolling (PageUp/Down/arrows), connection status dot, unread badge
- /help command, terminal bell on incoming DM, /devices + /kick commands
- 44 unit tests (types, input, draw with TestBackend)

Server — WZP Call Infrastructure (FC-2/3/5/6/7/10):
- Call state management (CallState, CallStatus, active_calls, calls + missed_calls sled trees)
- WS call signal awareness (Offer/Answer/Hangup update state, missed call on offline)
- Group call endpoint (POST /groups/:name/call with SHA-256 room ID, fan-out)
- Presence API (GET /presence/:fp, POST /presence/batch)
- Missed call flush on WS reconnect
- WZP relay config + CORS

Server — Security (FC-P1):
- Auth enforcement middleware (AuthFingerprint extractor on 13 write handlers)
- Session auto-recovery (delete corrupted ratchet, show [session reset])
- WS connection cap (5/fingerprint) + global concurrency limit (200)
- Device management (GET /devices, POST /devices/:id/kick, POST /devices/revoke-all)

Server — Federation:
- Two-server federation via JSON config (--federation flag)
- Periodic presence sync (every 5s, full-state, self-healing)
- Message forwarding via HTTP POST with SHA-256(secret||body) auth
- Graceful degradation (peer down = queue locally)
- deliver_or_queue() replaces push-or-queue in ws.rs + messages.rs

Client — Group Messaging:
- SenderKeyDistribution storage + GroupSenderKey decryption in TUI
- sender_keys sled tree in LocalDb

WASM:
- All 8 WireMessage variants handled (no more "unsupported")
- decrypt_group_message() + create_sender_key_from_distribution() exports
- CallSignal parsing with signal_type mapping

Docs:
- ARCHITECTURE.md rewritten with Mermaid diagrams
- README.md created
- TASK_PLAN.md with FC-P{phase}-T{task} naming
- PROGRESS.md updated to v0.0.21

WZP submodule updated to 6f4e8eb (IAX2 trunking, adaptive quality, metrics, all S-tasks done)

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

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

@@ -6,6 +6,8 @@ pub struct Database {
     pub groups: sled::Tree,
     pub aliases: sled::Tree,
     pub tokens: sled::Tree,
+    pub calls: sled::Tree,
+    pub missed_calls: sled::Tree,
     _db: sled::Db,
 }
 
@@ -17,12 +19,16 @@ impl Database {
         let groups = db.open_tree("groups")?;
         let aliases = db.open_tree("aliases")?;
         let tokens = db.open_tree("tokens")?;
+        let calls = db.open_tree("calls")?;
+        let missed_calls = db.open_tree("missed_calls")?;
         Ok(Database {
             keys,
             messages,
             groups,
             aliases,
             tokens,
+            calls,
+            missed_calls,
             _db: db,
         })
     }