chore: clean hydrotech-beam syncthing conflicts and add new docs

- Remove all .sync-conflict-* files
- Remove temp _temp_part_properties.json files
- Add USER_GUIDE.md
- Add dashboard docs (Executive, Technical, Operations, Master Plan)
- Add playbooks (DOE, NX_REAL_RUN, SYNCTHING_RECOVERY)
- Update iteration results

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

projects/hydrotech-beam/models/_temp_mass.txt

@@ -1 +1 @@
-p173=1343.5034206648418
+1343.5034206648418