TorChat v1.2.0 - Group Rooms

Group chat rooms, up to 16 people in one room.

The host now relays every message to everyone except the sender, so no
client talks directly to another and everyone sees the same conversation.
Each peer runs on its own thread, so people can talk over each other
instead of waiting for a turn.

Added

• Group rooms with a host relay, up to 16 peers
• Invite links carrying a 32-byte room secret per room
• Join and leave notices in the room
• Host commands: /list, /invite, /quit
• local_test.py with 12 relay, concurrency and framing checks

Changed

• Messages are length-prefixed before encryption and reassembled before
  decryption, so they no longer corrupt when the network splits or merges
  them. Previously a single recv() was assumed to return exactly one
  message, which broke as soon as more than two people talked at once.
• Invite links no longer use a one-time token, which does not scale past a
  single guest and would have been consumed by the first person to join.
• Duplicate display names are suffixed rather than silently colliding.

Fixed

• The input prompt is no longer overwritten by incoming messages, so typing
  is not garbled when someone talks while you are mid-sentence.
• The host now displays the messages it relays. It was forwarding them
  correctly but printing none, so a host watching guests talk saw an
  empty screen.

Security

• Removed the hardcoded shared-secret password that was compiled into
  both ends of the application. Anyone reading the source could have
  decrypted every room. Each room now generates 32 random bytes.

Not in this release

• Stealth authentication on the hidden service, persistent identities and
  message padding are still to come. See the roadmap in the README.