feat: add process management support (#207)

* feat: improve inspector UI for processes and fix PTY terminal

- Simplify ProcessRunTab layout: compact form with collapsible Advanced section for timeout/maxOutputBytes
- Rewrite ProcessesTab: collapsible create form, lightweight list items with status dots, clean detail panel with tabs
- Extract error details: use problem.detail instead of generic "Stream Error" title for better error messages
- Fix GhosttyTerminal binary frame parsing: handle server's binary ArrayBuffer control frames (ready/exit/error)
- Enable WebSocket proxying in Vite dev server with ws: true
- Set TERM=xterm-256color default for TTY processes so tools like tmux, vim, htop work out of the box
- Remove orange gradient background from terminal container for cleaner look
- Remove orange left border from selected process list items
- Update inspector CSS with new process/terminal styles

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

* fix: address review issues and add processes documentation

- Fix unstable onExit callback in ProcessesTab (useCallback)
- Fix SSE follow stream race condition (subscribe before history read)
- Update inspector.mdx with new process management features
- Change observability icon to avoid conflict with processes
- Add docs/processes.mdx covering the full process management API

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

* docs: simplify processes doc — rename sections, remove low-level protocol

- Rename "Interactive terminals" to "Terminals" with "Connect to a terminal" sub-heading
- Add TTY process creation step at top of Terminals section
- Remove low-level WebSocket protocol table and raw WebSocket example
- Keep browser terminal emulator reference with Ghostty link

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

* docs: update GhosttyTerminal permalink to latest commit

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

* docs: use main branch permalink for GhosttyTerminal reference

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

* feat: refine process API — WebSocket binary protocol, SDK terminal session, updated tests

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

* docs: update GhosttyTerminal permalink to 636eefb

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

* inspector: use websocket terminal API

* sdk: restore high-level terminal session

* docs: update inspector terminal permalink

* inspector: update run once placeholder

* Fix lazy install v1 API test fixture

* Add reusable React terminal component

* Fix terminal WebSocket ready state checks

---------

Co-authored-by: Claude Haiku 4.5 <noreply@anthropic.com>

frontend/CLAUDE.md

@@ -1,26 +1,4 @@
 # Frontend Instructions
 
-## Inspector Architecture
-
-- Inspector source is `frontend/packages/inspector/`.
-- `/ui/` must use ACP over HTTP (`/v2/rpc`) for session/prompt traffic.
-- Primary flow:
-  - `initialize`
-  - `session/new`
-  - `session/prompt`
-  - `session/update` over SSE
-- Keep backend/protocol changes in client bindings; avoid unnecessary full UI rewrites.
-
-## Testing
-
-Run inspector checks after transport or chat-flow changes:
-```bash
-pnpm --filter @sandbox-agent/inspector test
-pnpm --filter @sandbox-agent/inspector test:agent-browser
-```
-
-## Docs Sync
-
-- Update `docs/inspector.mdx` when `/ui/` behavior changes.
-- Update `docs/sdks/typescript.mdx` when inspector SDK bindings or ACP transport behavior changes.
-
+- When the user asks for UI changes, capture screenshots of the updated UI after implementation and verification.
+- At the end, offer to open those screenshots for the user and provide absolute filesystem paths to the screenshot files.