feat: agor-pty crate — standalone PTY multiplexer daemon (Phase 1 WIP)

New crate at agor-pty/ (standalone, not in workspace — portable to Tauri/Electrobun):
- Rust daemon (agor-ptyd) with Unix socket IPC, JSON-framed protocol
- PTY session lifecycle: create, resize, write, close, output fanout
- 256-bit token auth, multi-client support, session persistence
- TypeScript IPC client at clients/ts/pty-client.ts (Bun + Node.js)
- Protocol: 9 client messages, 7 daemon messages
- Based on tribunal ruling (78% confidence, 4 rounds, 55 objections)

WIP: Rust implementation in progress (protocol.rs + auth.rs done)

agor-pty/README.md

@@ -0,0 +1,90 @@
+# agor-pty — PTY Multiplexer Daemon
+
+Standalone Rust daemon that manages terminal sessions via Unix socket IPC.
+Portable across Tauri and Electrobun frontends.
+
+## Architecture
+
+```
+Frontend (Electrobun/Tauri)
+    ↕ Unix Socket IPC (JSON-framed)
+agor-ptyd (Rust daemon)
+    ↕ PTY master FDs
+Shell processes (/bin/bash, etc.)
+```
+
+## Features
+
+- **PTY multiplexing**: single daemon manages all terminal sessions
+- **Session persistence**: sessions survive frontend disconnects/restarts
+- **Multi-client**: multiple frontends can connect and subscribe to session output
+- **Auth**: 256-bit token authentication per connection
+- **Output fanout**: PTY output fanned to all subscribed clients (non-blocking)
+- **Graceful shutdown**: SIGTERM/SIGINT cleanup
+
+## Usage
+
+```bash
+# Build
+cd agor-pty && cargo build --release
+
+# Run daemon
+./target/release/agor-ptyd --verbose
+
+# Custom socket directory
+./target/release/agor-ptyd --socket-dir /tmp/agor-test
+
+# Custom default shell
+./target/release/agor-ptyd --shell /bin/zsh
+```
+
+## IPC Protocol
+
+JSON messages over Unix socket, newline-delimited.
+
+### Client → Daemon
+- `Auth { token }` — authenticate (must be first message)
+- `CreateSession { id, shell, cwd, env, cols, rows }` — spawn shell
+- `WriteInput { session_id, data }` — send input to PTY
+- `Resize { session_id, cols, rows }` — resize terminal
+- `Subscribe { session_id }` — receive output from session
+- `Unsubscribe { session_id }` — stop receiving output
+- `CloseSession { session_id }` — kill session
+- `ListSessions` — get all active sessions
+- `Ping` — keepalive
+
+### Daemon → Client
+- `AuthResult { ok }` — auth response
+- `SessionCreated { session_id, pid }` — session spawned
+- `SessionOutput { session_id, data }` — PTY output (base64)
+- `SessionClosed { session_id, exit_code }` — session ended
+- `SessionList { sessions }` — list response
+- `Pong` — keepalive response
+- `Error { message }` — error
+
+## Integration
+
+### As library (for Tauri)
+```rust
+use agor_pty::protocol::{ClientMessage, DaemonMessage};
+```
+
+### TypeScript client (for Electrobun)
+See `clients/ts/` for the IPC client module.
+
+## Directory Structure
+
+```
+agor-pty/
+├── Cargo.toml
+├── README.md
+├── src/
+│   ├── main.rs        — daemon entry, CLI, signals
+│   ├── lib.rs         — library re-exports
+│   ├── protocol.rs    — IPC message types
+│   ├── session.rs     — PTY session management
+│   ├── daemon.rs      — Unix socket server
+│   └── auth.rs        — token authentication
+└── clients/
+    └── ts/            — TypeScript IPC client (for Electrobun/Bun)
+```