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/studies/01_doe_landscape/results/doe_summary.json

@@ -1,8 +1,8 @@
 {
-  "study_name": "hydrotech_beam_doe_phase1",
+  "study_name": "hydrotech_beam_doe_phase1_real",
   "phase": "Phase 1 \u2014 LHS DoE",
   "project": "Hydrotech Beam Structural Optimization",
-  "timestamp": "2026-02-11T16:40:12.707007+00:00",
+  "timestamp": "2026-02-14T22:24:29.123157+00:00",
   "configuration": {
     "n_lhs_samples": 50,
     "seed": 42,