Port probe methods to PIPChannel, add firmware lock, fix notebooks and setup

- Port clld_probe_z_height, plld_probe_z_height, ztouch_probe_z_height,
  clld_probe_y_position to PIPChannel with proper firmware call matching
- Port clld_probe_x_position to STARXArm
- Move move_y, move_tool_z, move_stop_disk_z, request_tip_length to PIPChannel
- Add move_to_z_safety (per-channel Px:ZA) replacing C0:ZA in probe methods
- Add FirmwareLock (readers-writer): Px commands parallel, C0 exclusive
- Fix notebook char-array serialization bugs across all STAR tutorials
- Reorganize probing notebooks into probing/ folder (x, y, z)
- Update all notebooks to use star.driver.pip / star.driver.iswap
- Add 96-head features: stamping, discard_tips, direct movement, trough support
- Fix setup: instrument pre-init, autoload init check, sequential C0 during setup
- Legacy backend forwards all ported methods to new implementations
- All tests pass, mypy clean

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: rickwierenga

docs/user_guide/hamilton/star/96head.ipynb

@@ -114,7 +114,7 @@
     "  plate[\"A1:C1\"],\n",
     "  vols=[100.0, 50.0, 200.0],\n",
     "  backend_params=STARPIPBackend.AspirateParams(\n",
-    "  hamilton_liquid_classes=[HighVolumeFilter_Water_DispenseSurface_Part] * 3,\n",
+    "    hamilton_liquid_classes=[HighVolumeFilter_Water_DispenseSurface_Part] * 3,\n",
     "  ),\n",
     ")"
    ]
@@ -147,11 +147,11 @@
     "  plate[\"A1:C1\"],\n",
     "  vols=[100.0, 50.0, 200.0],\n",
     "  backend_params=STARPIPBackend.AspirateParams(\n",
-    "  hamilton_liquid_classes=[\n",
-    "   HighVolumeFilter_Water_DispenseSurface_Part,\n",
-    "   HighVolumeFilter_EtOH_DispenseJet,\n",
-    "   HighVolumeFilter_DMSO_AliquotDispenseJet_Part,\n",
-    "  ],\n",
+    "    hamilton_liquid_classes=[\n",
+    "      HighVolumeFilter_Water_DispenseSurface_Part,\n",
+    "      HighVolumeFilter_EtOH_DispenseJet,\n",
+    "      HighVolumeFilter_DMSO_AliquotDispenseJet_Part,\n",
+    "    ],\n",
     "  ),\n",
     ")"
    ]