Update AGENTS.md: remove obsolete submodule push instructions, add dataset viewer agent rules and tmux workflow

AGENTS.md

@@ -87,7 +87,6 @@ The GoPro USB controller lives in `clients/gopro-scicam/` as part of this repo (
   git push -u origin master
   git remote set-url origin https://git.telavivmakers.space/tami/REPO.git
   ```
-
 ### Dashboard (`dashboard/`)
 
 Terminal UI for monitoring and auto-syncing multiple SciCam devices to `~/timi/capture`.
@@ -237,6 +236,27 @@ rerun output.rrd
 - **Timeline plots**: ISO, exposure, aperture, focal length, AE/AWB lock over time
 - **Blueprint layout**: Image gallery, metadata panel, and time-series plots
 
+**Agent instruction: running the viewer**
+If the user asks to run the dataset viewer (or anything related to it), assume they want it in a **tmux window named `runio`** inside the *current* tmux session. Create the window if it does not exist, kill any previous viewer process in that window, and start the viewer with `--serve` there. Do not spawn detached background processes.
+
+When using `--serve`, the Rerun **web viewer is on port 9090** (not 9876). Port 9876 is the internal gRPC proxy and will return 400 to browsers. Use `fedora.lan` (not raw IP) when telling the user the URL.
+
+## Network Hostnames
+
+When the user mentions machines by short name (`devdesk`, `fedora`, `eight`, `pop-os`), resolve them by appending `.lan` — e.g. `fedora.lan`, `eight.lan`. These are the LAN hostnames known to all machines on the network. Do not use raw IPs unless explicitly told to.
+
+## Tmux Workflow
+
+Long-running services run in named windows inside the user's existing tmux session (never as detached background processes). Check `$TMUX` / `$STY` to detect if already inside a multiplexer.
+
+| Window | Purpose | Command / Notes |
+|--------|---------|-----------------|
+| `tdash` | SciCam dashboard | `cd dashboard && ./target/release/scicam-dashboard` |
+| `runio` | Rerun dataset viewer | `./tools/dataset_viewer.py ... --serve` (port 9090) |
+| `gopro` | GoPro USB client | `cd clients/gopro-scicam && python app.py` (port 5000) |
+
+**Agent rule:** If asked to start a service and you are inside tmux, open/reuse the dedicated window above (create it if missing, kill any previous process in that window first). If not inside tmux, create a new session named after the service as a fallback.
+
 ## Future Roadmap (do not break)
 
 - This is an **archive and dataset for audio-visual inventory**. Treat existing files as immutable.