docs: Local PTY Copilot Panel design spec

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docs/superpowers/specs/2026-03-24-local-pty-copilot-design.md

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+# Local PTY Copilot Panel — Design Spec
+
+**Date:** 2026-03-24
+**Status:** Approved
+**Author:** Claude Opus 4.6 (XO)
+
+## Problem
+
+The AI panel is a Gemini API stub (~130 lines backend, ~124 lines frontend) with no OAuth, no conversation history, no tool use. The Commander pays $200/mo Claude Max, $20/mo Gemini, $20/mo ChatGPT — all of which include CLI tool access (Claude Code, Gemini CLI, Codex CLI). These CLIs are designed for terminals. Wraith has a terminal. Ship a local PTY in the sidebar and let the user run whichever CLI they want.
+
+## Solution
+
+Replace the Gemini stub with a local PTY terminal in the sidebar panel. Reuse the existing xterm.js infrastructure. User picks a shell (bash, sh, zsh, PowerShell, Git Bash), the panel spawns it locally, and they run `claude`, `gemini`, `codex`, or anything else.
+
+## Architecture
+
+### Backend — `src-tauri/src/pty/mod.rs`
+
+New module following the same patterns as `SshService`:
+
+```
+PtyService
+  sessions: DashMap<String, Arc<PtySession>>
+
+PtySession
+  id: String
+  writer: Mutex<Box<dyn Write + Send>>       // from master.take_writer()
+  master: Mutex<Box<dyn MasterPty + Send>>    // kept for resize()
+  child: Mutex<Box<dyn Child + Send + Sync>>  // for kill/wait
+  shell_path: String
+
+PtyService methods:
+  spawn(shell_path, cols, rows, app_handle) -> Result<String, String>
+  write(session_id, data) -> Result<(), String>
+  resize(session_id, cols, rows) -> Result<(), String>
+  disconnect(session_id) -> Result<(), String>
+  list_shells() -> Vec<ShellInfo>
+```
+
+Note: `writer` and `master` require `Mutex` wrappers because `portable-pty` trait objects are `Send` but not `Sync`, and the `DashMap` requires `Sync` on stored values.
+
+**PTY crate:** `portable-pty` — cross-platform (Unix PTY, Windows ConPTY). MIT licensed. Part of the wezterm project.
+
+**Shell detection** (`list_shells`):
+- Unix: check existence of `/bin/bash`, `/bin/sh`, `/bin/zsh`, `$SHELL`
+- Windows: `powershell.exe`, `cmd.exe`, plus scan for Git Bash at common paths (`C:\Program Files\Git\bin\bash.exe`, `C:\Program Files (x86)\Git\bin\bash.exe`)
+- Return `Vec<ShellInfo>` with `{ name, path }` pairs
+
+**Output loop** — spawned per session via `spawn_blocking` (not async — `portable-pty` reader is synchronous `std::io::Read`):
+```rust
+tokio::task::spawn_blocking(move || {
+    let mut reader = BufReader::new(pty_reader);
+    let mut buf = [0u8; 4096];
+    loop {
+        match reader.read(&mut buf) {
+            Ok(0) => { app.emit("pty:close:{id}", ()); break; }
+            Ok(n) => { app.emit("pty:data:{id}", base64(&buf[..n])); }
+            Err(_) => break;
+        }
+    }
+});
+```
+
+`AppHandle::emit()` is synchronous in Tauri v2, so it works from a blocking thread context without issues.
+
+**Environment:** `CommandBuilder` inherits the parent process environment by default. This is required so that `PATH` includes the user's CLI tools (`claude`, `gemini`, `codex`). No env filtering should be applied.
+
+### Backend — Tauri Commands (`src-tauri/src/commands/pty_commands.rs`)
+
+```rust
+spawn_local_shell(shell_path: String, cols: u32, rows: u32) -> Result<String, String>
+pty_write(session_id: String, data: String) -> Result<(), String>
+pty_resize(session_id: String, cols: u32, rows: u32) -> Result<(), String>
+disconnect_pty(session_id: String) -> Result<(), String>
+list_available_shells() -> Result<Vec<ShellInfo>, String>
+```
+
+All registered in `lib.rs` invoke handler. All added to `capabilities/default.json`.
+
+### Backend — AppState Changes
+
+```rust
+pub struct AppState {
+    // ... existing fields ...
+    pub pty: PtyService,        // ADD
+    // pub gemini: Mutex<...>,  // DELETE
+}
+```
+
+### Frontend — `src/components/ai/CopilotPanel.vue`
+
+Replaces `GeminiPanel.vue`. Structure:
+
+1. **Header bar:** "AI Copilot" title + shell selector dropdown + spawn/kill buttons
+2. **Terminal area:** xterm.js instance via `useTerminal` composable (adapted for PTY events)
+3. **State:** shell list (from `list_available_shells`), active session ID, connected flag
+4. **Close handling:** Listen for `pty:close:{session_id}` events to update `connected` state and show "Session ended — Relaunch?" UI. This differs from the SSH path where tab closure handles cleanup.
+
+Shell selector is a `<select>` dropdown populated on mount. "Launch" button calls `spawn_local_shell`. Terminal mounts when session starts.
+
+**Initial terminal size:** On spawn, measure terminal dimensions via `fitAddon.fit()` before invoking `spawn_local_shell`. Pass the measured cols/rows. If the terminal is not yet mounted, use defaults (80x24) and immediately resize after mount.
+
+### Frontend — `useTerminal` Adaptation
+
+Current `useTerminal.ts` hardcodes `ssh_write`, `ssh_resize`, and `ssh:data:` events.
+
+**Chosen approach:** Parameterize the composable to accept a "backend type":
+```typescript
+export function useTerminal(sessionId: string, backend: 'ssh' | 'pty' = 'ssh')
+```
+
+- `backend === 'ssh'` → `invoke("ssh_write")`, `listen("ssh:data:{id}")`, `convertEol: true`
+- `backend === 'pty'` → `invoke("pty_write")`, `listen("pty:data:{id}")`, `convertEol: false`
+
+Same xterm.js instance, same resize observer, same clipboard, same base64 decode. Only the invoke target, event prefix, and EOL conversion change.
+
+**Important:** The local PTY driver already translates LF to CRLF. The SSH path needs `convertEol: true` because raw SSH streams may send bare LF. Setting `convertEol: true` on the PTY path would produce double newlines.
+
+### Cleanup — Delete Gemini Stub
+
+Remove entirely:
+- `src-tauri/src/ai/mod.rs`
+- `src-tauri/src/commands/ai_commands.rs`
+- `src/components/ai/GeminiPanel.vue`
+- `AppState.gemini` field and `Mutex<Option<ai::GeminiClient>>` in `lib.rs`
+- AI command registrations from invoke handler
+- `pub mod ai;` from `lib.rs`
+
+Keep `reqwest` in `Cargo.toml` — the RDP stack (`ironrdp-tokio`, `sspi`) depends on it transitively and may require the `json` feature flag our direct dependency enables.
+
+### Data Flow
+
+```
+User types in copilot panel
+  → useTerminal.onData(data)
+  → invoke("pty_write", { sessionId, data })
+  → PtyService.write() → writer.write_all(data)
+  → PTY stdin → shell process
+
+Shell output → PTY stdout
+  → output reader loop (spawn_blocking)
+  → app.emit("pty:data:{id}", base64(bytes))
+  → useTerminal listener → base64 decode → xterm.js.write()
+
+Shell exits (user types "exit" or CLI tool quits)
+  → reader returns Ok(0)
+  → app.emit("pty:close:{id}", ())
+  → CopilotPanel listens → updates connected state → shows relaunch UI
+```
+
+### Tauri ACL
+
+No changes needed to `capabilities/default.json` — `core:default` covers command invocation, `core:event:default` covers event listening. The PTY commands are registered via `generate_handler!`.
+
+### Testing
+
+**Rust tests:**
+- `list_shells()` returns at least one shell on any platform
+- `spawn()` + `write("echo hello\n")` + read output contains "hello"
+- `resize()` doesn't error on active session
+- `disconnect()` removes session from registry
+- `disconnect()` on nonexistent session returns error
+
+**Frontend:** `useTerminal` composable already tested via SSH path. The `backend` parameter is a simple branch — no separate test needed.
+
+### Dependencies
+
+**Add:**
+- `portable-pty` — cross-platform PTY (MIT license, part of wezterm project)
+
+**No removals** — `reqwest`, `md5`, `pem`, and other existing deps serve SSH and RDP functionality.
+
+### Migration
+
+No data migration needed. The Gemini stub stores nothing persistent — no DB tables, no settings, no vault entries. Clean delete.
+
+## Success Criteria
+
+1. Commander opens Wraith, presses Ctrl+Shift+G
+2. Shell dropdown shows detected shells (bash on macOS, PowerShell + Git Bash on Windows)
+3. Selects shell, clicks Launch
+4. Full interactive terminal appears in sidebar
+5. Types `claude` (or `gemini` or `codex`) — CLI launches, works normally
+6. Resize sidebar → terminal reflows
+7. Close panel or kill session → PTY process terminates cleanly
+8. Shell exits → panel shows "Session ended — Relaunch?" prompt