The editor GUI (stage 3 of 3): Unity projects, script fields, the live scene, agents in the session

Unity projects: a project folder (its first build scene) or a .unity file opens from the command line, File > Open Scene or File > Open Unity Project (scripts compile, nothing runs); saving to .unity patches the file the scene came from, as MCP's scene_save does; any scene still saves as JSON.
The inspector shows every field a component's type has, in declaration order: the runtime builds a new one on an inactive object ({"editor_component"}) and writes its fields as queries do; set fields have a button back to the default, the rest show dimmed at their defaults until edited. Integer fields edit as integers. Add Component lists the project's and loaded scripts and every engine component ({"editor_types"}).
While playing, the Hierarchy and Inspector show the live scene (the host's query, a few times a second; objects made while playing in italics), read-only.
Agents in the session: tassix_mcp is now a library. A Session works on a borrowed editor and script host, with the rest in a SessionState (Standalone owns all three for the stdio binary, whose behaviour is unchanged). The editor serves the same tools over MCP's Streamable HTTP on 127.0.0.1:47824 (--mcp-port; JSON responses, no event stream; non-local Host or Origin refused), answered on the main thread between frames on the editor's own scene and engine: agent edits are transactions in the same history and review, play mode is one (an agent's play_step shows the game here, paused between its steps; the person's Play is the agent's play mode), an agent's scene_open opens the scene here.
The Agents pane replaces the web review panel in the editor: the claude mcp add command, who is connected and their last tool, edit and code permission levels, code waiting to run, every agent transaction with its changes and Accept, Revert, Approve, Reject (the review panel's actions, on the same session).
Tests: a Unity project copy opens, offers its scripts with their fields, saves a rename as a new .unity and reopens it (in-process runtime); an HTTP client initializes, edits, queries, steps and stops play while the editor UI runs (kittest), its edit arrives as its pending transaction and Revert in the Agents pane takes it back; a foreign Origin is refused. MCP's e2e and launcher tests pass unchanged.
Not yet: resource update notifications for HTTP clients (no event stream); editing the live scene while playing; the inspector's object references and assets beyond JSON; agent presence in the views (what it last touched); the TrailRenderer blob and handles over objects from stage 2.
Next: the editor's remaining gaps above as they matter; Phase 6 continues alongside.