Split session daemon from web server

README.md

@@ -8,7 +8,7 @@ Small web wrapper around `@mariozechner/pi-coding-agent`.
 - Discover workspaces from `git worktree list --porcelain`.
 - For non-git projects, show the project folder as the only workspace.
 - List Pi sessions for a workspace using Pi's default session storage.
-- Start Pi sessions, chat over WebSocket events, and close active runtimes.
+- Start Pi sessions, chat over WebSocket events, and stop individual session runtimes.
 
 ## State
 
@@ -17,7 +17,7 @@ This POC intentionally keeps state minimal:
 - Projects: `~/.pi-web/projects.json`
 - Workspaces: discovered from git, not stored
 - Sessions/chat history: Pi default JSONL session storage
-- Active sessions/WebSockets: memory only
+- Active session runtimes/WebSockets: memory only in `pi-web-sessiond`
 
 ## Run
 
@@ -28,19 +28,30 @@ npm run dev
 
 Open the Vite URL, usually <http://localhost:5173>.
 
-For a single-process/proxied deployment:
+The session runtime owner is split into a tiny long-lived daemon. To iterate on only the web/API/UI process while keeping active Pi sessions alive, run these in separate terminals:
+
+```bash
+npm run dev:sessiond
+npm run dev:web
+npm run dev:client
+```
+
+Then restart `dev:web` or `dev:client` freely; active Pi sessions continue in `dev:sessiond`.
+
+For deployment:
 
 ```bash
 npm run build
+npm run start:sessiond
 PI_WEB_PORT=3000 npm start
 ```
 
 Then proxy Traefik to `http://127.0.0.1:3000`.
 
-The server defaults to `127.0.0.1:3000`. Use `PI_WEB_HOST=0.0.0.0` only if you want to bind directly on all interfaces.
+The web server defaults to `127.0.0.1:3000`. Use `PI_WEB_HOST=0.0.0.0` only if you want to bind directly on all interfaces. The session daemon defaults to a private Unix socket at `~/.pi-web/sessiond.sock`; override with `PI_WEB_SESSIOND_SOCKET` or use TCP with `PI_WEB_SESSIOND_PORT` plus `PI_WEB_SESSIOND_URL` for the web process.
 
 ## Notes
 
 - The backend uses your normal Pi auth/model settings from `~/.pi/agent`.
 - Slash commands that belong to Pi's interactive TUI, such as `/model`, are not implemented in this POC UI yet. Plain prompts and extension/prompt-template handling go through the SDK path.
-- `Close` currently only disposes the in-memory runtime. It does not hide or delete sessions.
+- Browser disconnects and web-server restarts do not stop active Pi sessions. Only the explicit `Stop session` action aborts/disposes that one session runtime.