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>

apps/mcp/src/app/tools/issues.resolver.ts

@@ -46,6 +46,12 @@ const issueFields = {
     .optional()
     .describe('ISO date when work should start (roadmap)'),
   dueDate: z.string().optional().describe('ISO date, e.g. 2026-11-14'),
+  customFields: z
+    .record(z.string(), z.string().nullable())
+    .optional()
+    .describe(
+      'Custom field id → value (see get_project settings.customFields): SELECT one of its options, DATE YYYY-MM-DD, NUMBER a number. Only the fields to change; null clears one',
+    ),
 };
 
 type IssueFields = {
@@ -57,6 +63,7 @@ type IssueFields = {
   storyPoints?: number;
   startDate?: string;
   dueDate?: string;
+  customFields?: Record<string, string | null>;
 };
 
 @Resolver()
@@ -142,6 +149,12 @@ export class IssuesResolver {
         .describe('Only the tickets the user follows'),
       dueFrom: z.string().optional().describe('Due on or after (ISO date)'),
       dueTo: z.string().optional().describe('Due on or before (ISO date)'),
+      customFields: z
+        .record(z.string(), z.string())
+        .optional()
+        .describe(
+          'Only tickets holding these custom values (field id → value)',
+        ),
       sort: z
         .enum(['RECENT', 'RANK'])
         .default('RECENT')
@@ -170,6 +183,7 @@ export class IssuesResolver {
       watching?: boolean;
       dueFrom?: string;
       dueTo?: string;
+      customFields?: Record<string, string>;
       sort: 'RECENT' | 'RANK';
       limit: number;
       offset: number;
@@ -198,6 +212,11 @@ export class IssuesResolver {
               watching: params.watching,
               dueFrom: params.dueFrom,
               dueTo: params.dueTo,
+              field: params.customFields
+                ? Object.entries(params.customFields).map(
+                    ([id, value]) => `${id}:${value}`,
+                  )
+                : undefined,
               sort: params.sort,
               limit: params.limit,
               offset: params.offset,