Portable Ithaca capture node: one install for every Jetson

Extract the install that was applied by hand to the Jetson Nano into a single
checkout that builds itself for whatever Jetson it lands on.

The two nodes on the rig share no JetPack — tegra210 caps at 4, tegra234 needs
5+ — so nothing binary is portable between them. The source and the procedure
are: install.sh detects the platform (L4T / JetPack / SoC), installs deps,
builds the OrbbecSDK and the preview server from source locally, and generates
a per-user config and systemd unit. The tested bridge.py ships verbatim; all
machine-specific paths live in the generated config, so it stays unmodified —
its one hardcoded path is made home-relative.

The retired GStreamer/RTSP target is dropped: the direct route encodes no video.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

bridge/config.template.json

@@ -0,0 +1,9 @@
+{
+  "server_ip": null,
+  "working_directory": "@HOME@/IthacaRecordings",
+  "recorder_bin": "@SDK_BUILD@/bin/ob_stream_depth_color_k4arec_pipeline",
+  "stream_server": "@REPO@/server/build/ithaca_rgbd_server",
+  "sync_mode": "standalone",
+  "camera_serial": null,
+  "log_level": "INFO"
+}