refactor: rename ws adapter to server across codebase

'ws' conflated storage mode with transport protocol (WebSocket). Renamed for
clarity: the adapter talks the self-hosted server (src/storage/server.js), which
happens to use WebSocket for realtime — but the name should describe what it
connects to, not how.

Renames:
- src/storage/ws.js -> server.js
- createWsStorage() -> createServerStorage()
- storage mode 'ws' -> 'server'
- REACT_APP_BACKEND_WS -> REACT_APP_BACKEND_REALTIME_URL
- factory param wsUrl -> realtimeUrl
- server/tests/ws-*.test.js -> server-*.test.js

Kept literal: 'ws' npm package, ws:// protocol URLs, /ws WebSocket endpoint.
Transport is accurate there; only storage-naming changed.

Updated all docs (DEVELOPMENT, TESTING, REWORK_PLAN, GLOSSARY, TODO), scripts
(dev-start.sh, replay-combat.js), factory + ESM tests. 204 tests green.

scripts/dev-start.sh

@@ -1,5 +1,5 @@
 #!/usr/bin/env bash
-# Start local dev stack: node backend (sqlite) + react frontend, ws storage mode.
+# Start local dev stack: node backend (sqlite) + react frontend, server storage mode.
 # Usage: ./scripts/dev-start.sh
 # Stop:  ./scripts/dev-stop.sh
 set -euo pipefail
@@ -25,12 +25,12 @@ else
   echo "backend already on :4001"
 fi
 
-# frontend: ws storage, :3999
+# frontend: server storage, :3999
 if ! lsof -ti :3999 >/dev/null 2>&1; then
   echo "starting frontend :3999..."
-  REACT_APP_STORAGE=ws \
+  REACT_APP_STORAGE=server \
   REACT_APP_BACKEND_URL=http://127.0.0.1:4001 \
-  REACT_APP_BACKEND_WS=ws://127.0.0.1:4001/ws \
+  REACT_APP_BACKEND_REALTIME_URL=ws://127.0.0.1:4001/ws \
   BROWSER=none PORT=3999 \
     nohup npm start > tmp/fe.log 2>&1 &
   echo $! > tmp/fe.pid