feat: Add smart density defaults based on material type (#2)

Auto-fill density when entering material type in filament forms:
- Add materialDefaults.ts with standard densities for common materials
  (PLA, ABS, PETG, TPU, PC, etc.)
- Material field now uses AutoComplete with suggestions
- Density auto-fills on material select or blur (fuzzy matching)
- New filaments default to 1.75mm diameter and 1.24 g/cm³ (PLA)
- Applied to both full filament create page and quick create modal

Reduces tedious data entry for common materials while still allowing
custom values for specialty filaments.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

client/src/pages/filaments/create.tsx

@@ -1,15 +1,21 @@
 import { Create, useForm, useSelect } from "@refinedev/antd";
 import { HttpError, IResourceComponentsProps, useInvalidate, useTranslate } from "@refinedev/core";
-import { Button, ColorPicker, Divider, Form, Input, InputNumber, Radio, Select, Typography } from "antd";
+import { AutoComplete, Button, ColorPicker, Divider, Form, Input, InputNumber, Radio, Select, Typography } from "antd";
 import { PlusOutlined } from "@ant-design/icons";
 import TextArea from "antd/es/input/TextArea";
 import dayjs from "dayjs";
 import utc from "dayjs/plugin/utc";
-import { useEffect, useState } from "react";
+import { useEffect, useMemo, useState } from "react";
 import { ExtraFieldFormItem, ParsedExtras, StringifiedExtras } from "../../components/extraFields";
 import { FilamentImportModal } from "../../components/filamentImportModal";
 import { VendorCreateModal } from "../../components/vendorCreateModal";
 import { MultiColorPicker } from "../../components/multiColorPicker";
+import {
+  DEFAULT_DENSITY,
+  DEFAULT_DIAMETER,
+  getDensityForMaterial,
+  KNOWN_MATERIALS,
+} from "../../utils/materialDefaults";
 import { formatNumberOnUserInput, numberParser, numberParserAllowEmpty } from "../../utils/parsing";
 import { ExternalFilament } from "../../utils/queryExternalDB";
 import { EntityType, useGetFields } from "../../utils/queryFields";
@@ -36,6 +42,15 @@ export const FilamentCreate: React.FC<IResourceComponentsProps & CreateOrClonePr
   const [isVendorModalOpen, setIsVendorModalOpen] = useState(false);
   const invalidate = useInvalidate();
   const [colorType, setColorType] = useState<"single" | "multi">("single");
+  const [materialSearch, setMaterialSearch] = useState("");
+
+  // Material options for AutoComplete
+  const materialOptions = useMemo(() => {
+    const filtered = materialSearch
+      ? KNOWN_MATERIALS.filter((m) => m.toLowerCase().includes(materialSearch.toLowerCase()))
+      : KNOWN_MATERIALS;
+    return filtered.map((material) => ({ value: material, label: material }));
+  }, [materialSearch]);
 
   const { form, formProps, formLoading, onFinish, redirect } = useForm<
     IFilament,
@@ -56,6 +71,10 @@ export const FilamentCreate: React.FC<IResourceComponentsProps & CreateOrClonePr
 
     // Parse the extra fields from string values into real types
     formProps.initialValues = ParsedExtras(formProps.initialValues);
+  } else {
+    // Set defaults for new filaments
+    formProps.initialValues.density = formProps.initialValues.density ?? DEFAULT_DENSITY;
+    formProps.initialValues.diameter = formProps.initialValues.diameter ?? DEFAULT_DIAMETER;
   }
 
   const handleSubmit = async (redirectTo: "list" | "create") => {
@@ -79,6 +98,14 @@ export const FilamentCreate: React.FC<IResourceComponentsProps & CreateOrClonePr
     setIsVendorModalOpen(false);
   };
 
+  // Auto-fill density when material is selected or entered
+  const handleMaterialChange = (value: string) => {
+    const density = getDensityForMaterial(value);
+    if (density !== undefined) {
+      form.setFieldValue("density", density);
+    }
+  };
+
   const importFilament = async (filament: ExternalFilament) => {
     const vendor = await getOrCreateVendorFromExternal(filament.manufacturer);
     await invalidate({
@@ -265,7 +292,14 @@ export const FilamentCreate: React.FC<IResourceComponentsProps & CreateOrClonePr
             },
           ]}
         >
-          <Input maxLength={64} />
+          <AutoComplete
+            options={materialOptions}
+            onSearch={setMaterialSearch}
+            onSelect={handleMaterialChange}
+            onBlur={(e) => handleMaterialChange((e.target as HTMLInputElement).value)}
+            placeholder={t("filament.form.material_placeholder")}
+            maxLength={64}
+          />
         </Form.Item>
         <Form.Item
           label={t("filament.fields.price")}