Rename the project to FieldCraft

Crates fieldcraft-*, binaries fieldcraft and fieldcraft-cli, the .fieldcraft file (format tag
fieldcraft/1, manifest fieldcraft.json), FIELDCRAFT_* environment variables, the MCP server
name, egui widget ids (fc_*), the app icon document FieldCraft.icon and its generated family,
docs and licences. No compatibility shim: no files of the earlier name exist.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

crates/decks/tests/abaqus/cantilever.inp

@@ -1,6 +1,6 @@
 *HEADING
-ModelCraft model, units mm-t-s-N-MPa
-** Written by ModelCraft. The numbers are in one consistent unit system and are not converted.
+FieldCraft model, units mm-t-s-N-MPa
+** Written by FieldCraft. The numbers are in one consistent unit system and are not converted.
 ** Nodes
 *NODE
 1, 0.0, 0.0, 0.0

crates/decks/tests/abaqus/frequency.inp

@@ -1,6 +1,6 @@
 *HEADING
-ModelCraft model, units mm-t-s-N-MPa
-** Written by ModelCraft. The numbers are in one consistent unit system and are not converted.
+FieldCraft model, units mm-t-s-N-MPa
+** Written by FieldCraft. The numbers are in one consistent unit system and are not converted.
 ** Nodes
 *NODE
 1, 0.0, 0.0, 0.0

crates/decks/tests/abaqus/plate.inp

@@ -1,6 +1,6 @@
 *HEADING
-ModelCraft model, units mm-t-s-N-MPa
-** Written by ModelCraft. The numbers are in one consistent unit system and are not converted.
+FieldCraft model, units mm-t-s-N-MPa
+** Written by FieldCraft. The numbers are in one consistent unit system and are not converted.
 ** Nodes
 *NODE
 1, 0.0, 0.0, 0.0