feat: add synthetic UR5e degradation dataset

data/synthetic/ur5e_degradation.parquet

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+version https://git-lfs.github.com/spec/v1
+oid sha256:a71c9eca47bcfd96d71fd3bd1fbbf3c13f94784905948243500990f0e0a2dcd2
+size 2968852

data/synthetic/ur5e_degradation_meta.json

@@ -0,0 +1,89 @@
+{
+  "n_runs": 108,
+  "cycles_per_run": 300,
+  "total_rows": 32400,
+  "rul_cap": 300,
+  "n_features": 14,
+  "feature_cols": [
+    "j1_vel",
+    "j2_vel",
+    "j3_vel",
+    "j4_vel",
+    "j5_vel",
+    "j6_vel",
+    "j1_trq",
+    "j2_trq",
+    "j3_trq",
+    "j4_trq",
+    "j5_trq",
+    "j6_trq",
+    "payload_norm",
+    "speed_norm"
+  ],
+  "metadata_cols": [
+    "unit_id",
+    "cycle",
+    "rul",
+    "rul_norm",
+    "wear_state",
+    "degraded_joint",
+    "fault_mode",
+    "severity",
+    "condition_id"
+  ],
+  "fault_modes": [
+    "friction",
+    "backlash",
+    "stiffness"
+  ],
+  "severities": [
+    2.0,
+    5.0,
+    10.0
+  ],
+  "conditions": [
+    {
+      "condition_id": 0,
+      "payload_norm": 0.2,
+      "speed_norm": 0.3,
+      "description": "light payload, slow speed"
+    },
+    {
+      "condition_id": 1,
+      "payload_norm": 0.8,
+      "speed_norm": 0.8,
+      "description": "heavy payload, fast speed"
+    }
+  ],
+  "n_joints": 6,
+  "robot": "UR5e",
+  "mjcf_source": "MuJoCo Menagerie (BSD-3-Clause)",
+  "physics_params": {
+    "baseline_frictionloss_Nm": [
+      0.8,
+      1.2,
+      0.9,
+      0.4,
+      0.3,
+      0.25
+    ],
+    "baseline_damping_Nms_rad": [
+      0.3,
+      0.4,
+      0.3,
+      0.15,
+      0.12,
+      0.1
+    ],
+    "baseline_gainprm_Nm_rad": [
+      500.0,
+      500.0,
+      400.0,
+      200.0,
+      200.0,
+      150.0
+    ],
+    "reference": "Robotica 2024, DOI:10.1017/S0263574724000833"
+  },
+  "quick": false
+}