Follow every run of the server in an Execution tab

[kineticsystem]

The editor could follow only the runs it started itself, through the feedback of its own goal. A run started from StepIt UI or the gamepad couldn't be seen, nor could a run already going when the page opened.

Two tabs in the centre panel: Editor and Execution.

• Execution shows the server's run, whoever started it: the tree as it runs, with each node's status.
• A run started elsewhere marks the Execution tab with its name, with a blue dot while it runs, but never takes the editor away. Opened, the tab says "started elsewhere".
• A run from the Run dialog opens the Execution tab and keeps Stop, as before. Only the editor's own runs can be stopped there.
• Nothing has run yet: the tab says so.
• Removed: the back arrow, "Back to the editor" and "Running X / Last run" buttons, which the tabs replace.

How:

• The editor follows /stepit_server/execution (stepit-commander PR), through rosbridge, from the moment it loads, and reconnects every 3 s.
• The topic is a setting under the Run dialog's Connection, next to the URL and the action; empty follows no topic.
• Its own run is recognised by the run number in its first feedback. From then on, the snapshots give its statuses, so a run looks the same whoever started it.
• The feedback stays as a fallback for servers that publish no run.
• A run started elsewhere shows once no run of the editor is going; it never replaces one. The goal's result, not the topic, ends the editor's own run.

Tests: 146 pass, 13 of them new:

• parsing the snapshots;
• following the topic and reconnecting;
• the store: an outside run, the next run replacing the last, the editor's own run recognised on the topic, its run kept until it ends, and the feedback fallback.

Checked in a browser on the rig, with fake motors:

• a run started from the command line marks the tab without leaving the editor;
• a page reloaded mid-run shows the running nodes at once and follows the run to "Succeeded";
• a run from the Run dialog shows Stop, and stopping ends it as "Stopped".

Docs: README (Running a Tree on the Robot, and the topic format under Monitoring a Run from Another Server) and docs/ARCHITECTURE.md. docs/execution.png still shows the old header, with its back arrow, and needs a new screenshot.

🤖 Generated with Claude Code