v0.4.0 - PTY Terminals, SSH Workbench & Multi-Session Architecture

New Features

• Interactive Local PTY Terminals & Web Terminal Drawer (PtyProcess, PtyManager, WebTerminal.js):
  • Native Unix pseudo-terminal execution using PHP's proc_open with ['pty'] descriptor on macOS/Linux with zero external C-extensions.
  • Non-blocking I/O integrated into Pig\Async\Loop, 16ms output micro-batching to prevent WebSocket frame storms, and slave PTY device detection (lsof on Darwin, /proc/$pid/fd/0 on Linux) with window resizing via stty + SIGWINCH.
  • Frontend integration with xterm.js and FitAddon multi-tab terminal drawer (accessible via Ctrl+\`` / Cmd+` or the top navigation terminal icon), with 200KB scrollback buffering and full support for interactive TUI tools (vim, nvim, nano, htop, tmux, less`).
• SSH Node Workbench & SFTP Remote File Explorer/Editor (NodeWorkbench.js, NodeManager, NodeProfile):
  • Persistent node inventory in ~/.pig/agent/nodes.json and credentials in ~/.pig/agent/nodes-secrets.json (chmod 0600).
  • SHA-256 host key fingerprint detection (ssh-keyscan + ssh-keygen -lf) with verification and trust prompts.
  • Automatic OpenSSH ~/.ssh/config host discovery and one-click import.
  • Remote interactive SSH terminal streaming via PTY (ssh -tt) and SFTP remote directory listing, navigation, and file reading/writing (capped at 512 KiB).
• Multi-Session Tab Multiplexing Architecture & Web Daemon:
  • Multiplexed multi-session tabs over a single physical WebSocket connection with per-tab chat scroll areas, background streaming indicators, and state recovery on reload.
  • Isolated pig --mode rpc child processes per cwd::sessionFile with 60s idle reaping and zero cross-session interference.
  • Native zero-dependency daemon management via pig web start|stop|status|restart [-d] and in-session /web restart, /web status, /web stop controls.
• Telegram-style Language Packs & Client-Side i18n Engine:
  • Full bilingual client-side I18N dictionary with 101 symmetric keys (defaulting to zh-CN), instant zero-refresh language modal (#lang-btn), Telegram-style JSON import/export, and $pig->registerLocale() on ExtensionApi with /api/locales aggregation.

Added

• Added externalEditor setting and intelligent fallback for Ctrl+G external prompt editing (aligned with upstream pi getExternalEditorCommand): precedence follows settings.externalEditor > $VISUAL > $EDITOR > platform fallback (notepad on Windows; nano / vim / vi on POSIX).
• Added ExtensionApi Phase 2 parity: EventBus, lifecycle hooks, tool loadout, context/session control, UI capabilities, and cross-handler state sharing via $ctx->set(), $ctx->get(), and $ctx->has().
• Added provider traffic hooks (before_provider_request, after_provider_response, before_retry) and dynamic provider registration (registerProvider), cleanly decoupling Google Antigravity into a standalone pure PHP extension.
• Added session title telemetry and speed meter integration in FooterComponent (pwd (branch) • <session-name>), session_info JSONL persistence, and /name slash command.
• Added model selection persistence control: session switches default to persistAsDefault: false (matching upstream pi), and Ctrl+S (app.models.save) explicitly saves the chosen model as global default.

Changed

• Enhanced SessionManager::open() and SessionManager::describe() to use streaming line-by-line reading (fopen + fgets), reducing memory consumption on 70MB+ session files from >150MB to <10MB and preventing 128MB OOM crashes.
• Optimized session tree backtrace (SessionManager::pathTo()) by replacing O(N) array_unshift with O(1) append + single array_reverse, speeding up 28,000-node tree traversal from 718ms to 3ms (230x speedup).
• Optimized SessionManager::latestPathFor() with lightweight first-line sniffing, reducing pig -c session resume latency from 2275ms to 489ms.
• Optimized LRU cache eviction in Width::visible() from O(N) array_shift to O(1) hash eviction (unset), speeding up cache updates by 5.0x with capacity expanded to 2048.
• Aligned TextWrap::tokenize() with upstream pi's cjkBreakRegex for clean hyphenation and natural wrapping in mixed Chinese/English sentences.
• Updated Chars::isPunctuation() with Unicode punctuation matching (^[\p{P}\p{S}]\z/u) to recognize CJK punctuation as word boundaries for Ctrl+W / Alt+Backspace.

Fixed

• Fixed background fibers and subprocesses continuing to run on /quit while working: AgentSession::dispose() now cleanly aborts in-flight LLM streams, retries, compactions, and bash commands.
• Fixed Broken pipe and SSL zero-write loops on non-blocking OpenSSL transport failures: expanded Retry::WORDS regex to catch native SSL, handshake, and connection errors, and encapsulated fwrite/fread in warning-capturing error handlers.
• Fixed background process (&) pipe inheritance deadlock: added process state polling in Run::wait() to exit gracefully once the parent shell process terminates.
• Fixed silent LLM turn failures in Web mode: serialized lastError in AgentEndEvent and enhanced client-side error rendering with automatic input restoration.
• Fixed long quota reset errors displaying raw provider text: normalized to pi-style action guidance messages.
• Fixed top-level symbol redeclaration crashes on /reload and guarded extensions with tokenized symbol checks.