Initial commit — encrypted chat server + Python clients (v0.8.5)

E2E encrypted chat (X3DH + Double Ratchet, Signal Protocol).
Server: asyncio TCP + TLS, MySQL. Clients: PyQt6 GUI + CLI.
Secrets (.env, TLS keys, Cloudflare token), runtime data and
mobile clients (separate repos) are gitignored.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,19 @@
+# Secrets & runtime config
+.env
+certs/*.pem
+certs/cloudflare.ini
+
+# Python
+.venv/
+__pycache__/
+*.pyc
+
+# Runtime data
+uploads/
+
+# Local tooling
+.claude/settings.local.json
+
+# Mobile clients (separate repos)
+ios/
+Android/