feat: custom fields per project

Text, number, date or option-list fields defined in the project settings
(archived, never removed; their type is fixed once saved). Tickets hold
them, edited in the side panel, listed under the title and filtered by
option in the list view; also over GraphQL, REST (?field=ID:value) and MCP.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

libs/web/tracker/presenters/src/lib/pages/issue.page.ts

@@ -43,6 +43,7 @@ import {
   Attachment,
   Comment,
   DevLink,
+  Issue,
   IssueLink,
   IssueLinkType,
   IssuePriority,
@@ -70,6 +71,7 @@ import {
   MarkdownComponent,
 } from '../ui/markdown';
 import { RichEditorComponent } from '../ui/rich-editor';
+import { CustomFieldComponent } from '../ui/custom-field';
 
 const NONE = '';
 /** Same ceiling as the API's ATTACHMENTS_MAX_MB default. */
@@ -80,6 +82,7 @@ const MAX_FILE_BYTES = 25 * 1024 * 1024;
   changeDetection: ChangeDetectionStrategy.OnPush,
   imports: [
     BlockedComponent,
+    CustomFieldComponent,
     ReactionsComponent,
     MarkdownComponent,
     RichEditorComponent,
@@ -843,6 +846,16 @@ const MAX_FILE_BYTES = 25 * 1024 * 1024;
           >
             <pi-label>Área</pi-label>
           </pi-select-field>
+          @for (field of customFields(); track field.id) {
+            <ts-custom-field
+              [field]="field"
+              [value]="customValue(issue, field.id)"
+              [disabled]="!project.canContribute() || field.archived"
+              (valueChange)="
+                update({ customFields: [{ fieldId: field.id, value: $event }] })
+              "
+            />
+          }
 
           @if (!issue.trashedAt && canTrash(issue)) {
             <pi-action-button
@@ -1314,10 +1327,26 @@ export class IssuePage {
     storyPoints?: number | null;
     startDate?: string | null;
     dueDate?: string | null;
+    customFields?: { fieldId: string; value: string | null }[];
   }): void {
     this.facade.update(changes);
   }
 
+  /** The project's active fields, plus archived ones this ticket still has. */
+  protected readonly customFields = computed(() => {
+    const issue = this.facade.issue();
+    return (this.project.workflow().settings.customFields ?? []).filter(
+      (f) =>
+        !f.archived || !!issue?.customFields?.some((v) => v.fieldId === f.id),
+    );
+  });
+
+  protected customValue(issue: Issue, fieldId: string): string | null {
+    return (
+      issue.customFields?.find((v) => v.fieldId === fieldId)?.value ?? null
+    );
+  }
+
   protected link(): void {
     const targetKey = this.linkTarget();
     if (!targetKey) return;