Update README to reflect current codebase

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: rencryptofish

README.md

@@ -9,8 +9,7 @@
 Run multiple Claude, Codex, and Gemini agents in parallel, each in its own tmux session, managed from a single TUI.
 
 [![Rust](https://img.shields.io/badge/rust-stable-orange.svg)](https://www.rust-lang.org/)
-[![Tests](https://img.shields.io/badge/tests-passing-brightgreen.svg)](#testing)
-[![Coverage](https://img.shields.io/badge/coverage-65%25-yellow.svg)](#testing)
+[![CI](https://github.com/rencryptofish/hydra/actions/workflows/ci.yml/badge.svg)](https://github.com/rencryptofish/hydra/actions/workflows/ci.yml)
 [![License](https://img.shields.io/badge/license-MIT-blue.svg)](LICENSE)
 
 </div>
@@ -20,8 +19,8 @@ Run multiple Claude, Codex, and Gemini agents in parallel, each in its own tmux
 ## Features
 
 - **Sidebar + Preview layout** — browse all agent sessions in a list, see live output in the preview pane
-- **Compose mode** — press Enter to open compose, type a full message, press Enter to send, Esc to cancel (empty compose on Codex sends a bare Enter)
-- **Status indicators** — green (idle), red (running), yellow (exited) dots per session
+- **Compose mode** — press Enter to open compose, type a full message, press Enter to send, Esc to cancel (draft preserved). Prompt history with Up/Down arrows. Bracketed paste support for multiline input.
+- **Status indicators** — green (idle), red (running), yellow (exited) dots per session, with auto-clearing status messages
 - **Task timer** — tracks elapsed time for the current running task per agent
 - **Last message preview** — shows the last parsed assistant response per session from provider logs
 - **Auto-generated names** — sessions get NATO phonetic alphabet names (alpha, bravo, charlie, ...)
@@ -30,7 +29,8 @@ Run multiple Claude, Codex, and Gemini agents in parallel, each in its own tmux
 - **Diff tree** — sidebar shows per-file git diff stats grouped by directory
 - **Multi-agent support** — Claude (`claude --dangerously-skip-permissions`), Codex (`codex --yolo`), Gemini (`gemini --yolo`)
 - **Mouse support** — click to select sessions, scroll the preview pane
-- **Full scrollback** — scroll up through complete session history in the preview
+- **Full scrollback** — keyboard and mouse scrolling through complete session history (PgUp/PgDn, Home/End)
+- **Copy mode** — press `c` to release mouse capture for terminal text selection
 - **Low resource usage** — idle sessions skip pane captures, batch tmux queries, parallel agent resolution
 
 ## Requirements
@@ -56,51 +56,71 @@ To update later, run `hydra update`.
 ## Usage
 
 ```bash
-hydra              # launch the TUI
-hydra new NAME     # create a new agent session
-hydra ls           # list sessions
-hydra kill NAME    # kill a session
+hydra                    # launch the TUI
+hydra new AGENT NAME     # create a new agent session (claude/codex/gemini)
+hydra kill NAME          # kill a session
+hydra ls                 # list sessions for the current project
+hydra update             # update to the latest version from GitHub
 ```
 
 ### Keybindings
 
+**Browse mode**
+
 | Key | Action |
 |-----|--------|
+| `j` / `k` | Navigate sessions |
+| `PgUp` / `PgDn` | Scroll preview pane |
+| `Home` / `End` | Jump to top / bottom of preview |
+| `Enter` | Open compose mode |
 | `n` | New session |
 | `d` | Delete session |
-| `Enter` | Open compose / send in compose mode |
-| `Esc` | Cancel compose / cancel modal |
-| `j` / `k` | Navigate sessions |
-| `Scroll` | Scroll preview pane |
+| `c` | Toggle copy mode (release mouse for text selection) |
 | `q` | Quit |
 
+**Compose mode**
+
+| Key | Action |
+|-----|--------|
+| `Enter` | Send message |
+| `Shift+Enter` | Insert newline |
+| `Up` / `Down` | Browse prompt history |
+| `PgUp` / `PgDn` | Scroll preview pane |
+| `Esc` | Cancel (draft preserved) |
+
 ## Architecture
 
 Single-binary Rust TUI built on [ratatui](https://ratatui.rs) + [crossterm](https://docs.rs/crossterm) + [tokio](https://tokio.rs).
 
 ```
 src/
-├── main.rs       CLI parsing, event loop, key dispatch
-├── app.rs        UiApp state, mode machine (Browse/Compose/NewSessionAgent/ConfirmDelete)
-├── ui.rs         All ratatui rendering (snapshot tested)
-├── tmux.rs       SessionManager trait + subprocess tmux manager
+├── main.rs          CLI parsing, terminal setup, event loop
+├── app.rs           UiApp state, mode machine, key/mouse handlers
+├── backend.rs       Backend actor (owns all I/O, communicates via channels)
+├── backend/         Runtime sub-components (session, message, preview)
+├── agent/           Per-provider log parsing and command builders
+├── ui.rs            Root UI rendering (layout, draw dispatch)
+├── ui/              Rendering submodules (sidebar, preview, conversation, ...)
+├── tmux.rs          SessionManager trait + subprocess tmux manager
 ├── tmux_control.rs  Persistent `tmux -C` control-mode manager
-├── session.rs    Session/AgentType data types
-├── manifest.rs   Session persistence (~/.hydra/<project>/sessions.json)
-├── logs.rs       Claude/Codex/Gemini log readers + session/global stats
-└── event.rs      Async crossterm event reader
+├── session.rs       Session/AgentType data types
+├── manifest.rs      Session persistence (~/.hydra/<project>/sessions.json)
+├── logs.rs          Log readers + session/global stats + cost calculations
+├── event.rs         Async crossterm event reader
+└── system/          Git diff parsing, process tree helpers
 ```
 
 Key design decisions:
+- **Backend/UI actor model** — Backend runs in `tokio::spawn`, owns all I/O, and communicates with the UI via `watch` (state snapshots) and `mpsc` (commands, previews). The UI event loop never blocks on I/O.
 - **`SessionManager` trait** — all tmux interaction is behind an async trait for testability (mock/noop impls in tests)
-- **Hybrid status detection** — prefers tmux output/activity signals and falls back to capture-based detection when needed
+- **Hybrid status detection** — prefers tmux `%output` notifications and falls back to capture-based detection when needed
 - **Session revival** — manifest file persists session metadata; on startup, dead sessions are recreated with agent-specific resume commands
 - **Async I/O** — all tmux subprocess calls and manifest file I/O use `tokio` to avoid blocking the event loop
 - **Nested session isolation** — safely runs from within Claude Code by unsetting `CLAUDECODE` env vars in spawned sessions
 
 ## Testing
 
-450+ tests across unit, snapshot, CLI integration, and property-based:
+490+ tests across unit, snapshot, CLI integration, and property-based:
 
 ```bash
 cargo test                # run all tests