feat: propagate PL24 part metadata, improve auth UX with Google sign-in prominence

- Add unavailable/remark/modelCodes/presel fields to categories and parts DB schema
- Pass PL24 unavailable flag through pipeline instead of filtering out records
- Show unavailable categories/parts at reduced opacity in grid, tree, and parts panel
- Display part remark and model codes as secondary info in parts table
- Move Google sign-in button above email form on login/register pages with branded icon
- Add public email existence check endpoint for better login error messages
- Update INDEX.md documentation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/api/src/integrations/pl24/pl24.service.ts

@@ -908,8 +908,7 @@ export class PL24Service {
       records = responseData.groups as Array<Record<string, unknown>>;
     }
 
-    const availableRecords = records.filter((record) => {
-      if (record.unavailable) return false;
+    const validRecords = records.filter((record) => {
       const link = (record.link as Record<string, unknown>) || {};
       // Servicepart records have no link.path but can use bomBaseLink
       if (!link.path && !bomBasePath) return false;
@@ -918,7 +917,7 @@ export class PL24Service {
       return true;
     });
 
-    return availableRecords.map((record) => {
+    return validRecords.map((record) => {
       const values = (record.values as Record<string, string>) || {};
       const link = (record.link as Record<string, unknown>) || {};
 
@@ -950,11 +949,21 @@ export class PL24Service {
       );
       let name = separatorMatch ? separatorMatch[1].trim() : rawCaption;
 
-      const remarks = values.remarks || "";
+      const remarks = (values.remarks || "").replace(/\r?\n/g, " ").trim();
       if (remarks) {
         name = `${name} (${remarks})`;
       }
 
+      const modelDesc = (values.modelDescriptions || "").replace(/\r?\n/g, " ").trim();
+      if (modelDesc) {
+        name = `${name} [${modelDesc}]`;
+      }
+
+      const illusNum = (values.illustrationNumber || "").replace(/\\-/g, "-").trim();
+      if (illusNum) {
+        name = `${name} {${illusNum}}`;
+      }
+
       if (!name) name = code;
 
       // Construct linkPath: use record's own link.path, or bomBaseLink + record id
@@ -972,6 +981,7 @@ export class PL24Service {
         partCount: undefined,
         linkPath: constructedPath,
         linkWid: (link.wid as string) || (bomBasePath ? "servicePartsItemsTable" : undefined),
+        unavailable: !!record.unavailable,
       };
     });
   }
@@ -1042,6 +1052,8 @@ export class PL24Service {
         positionCode: String(part.pos || values.pos || ""),
         modelCodes,
         notes: modelCodes,
+        unavailable: !!part.unavailable,
+        presel: !!part.presel,
         superseded,
         hotspotId: (part.hotspotId as string) || undefined,
         linkPath: (part.link as Record<string, string>)?.path,
@@ -1324,6 +1336,7 @@ export class PL24Service {
         hotspotId: record.hotspotId || record.pos || undefined,
         quantity: parseInt(values.qty || "1", 10) || 1,
         modelCodes: values.restrictions || undefined,
+        presel: !!record.presel,
       };
     });
   }

apps/api/src/integrations/pl24/pl24.types.ts

@@ -462,6 +462,7 @@ export interface PL24MainGroup {
   subGroups?: PL24SubGroup[];
   linkPath?: string;
   linkWid?: string;
+  unavailable?: boolean;
 }
 
 export interface PL24SubGroup {
@@ -471,6 +472,7 @@ export interface PL24SubGroup {
   description?: string;
   imageUrl?: string;
   partCount?: number;
+  unavailable?: boolean;
 }
 
 export interface PL24Part {
@@ -484,6 +486,8 @@ export interface PL24Part {
   positionCode?: string;
   modelCodes?: string;
   notes?: string;
+  unavailable?: boolean;
+  presel?: boolean;
   superseded?: {
     oldCode: string;
     newCode: string;