feat: attachments on tickets and comments

Files are uploaded over REST, stored on disk (a volume in Docker) and
recorded on the ticket as events; the bytes are written first, so no
attachment ever points at a missing file. Only images, video, audio, PDF
and plain text are shown inline, everything with nosniff and a sandbox CSP.
The web shows thumbnails, uploads by drag and drop or by pasting a
screenshot, and attaches files to new comments.

Also adds `nx run api:contracts`, which writes schema.gql and
openapi.json without starting the API or any database.

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

libs/web/tracker/application/src/lib/stores/issue.store.ts

@@ -11,6 +11,7 @@ import { AuthFacade } from '@task-stream/web/identity/application';
 import {
   Activity,
   ActivityGateway,
+  AttachmentsGateway,
   Comment,
   CommentsGateway,
   Issue,
@@ -18,8 +19,11 @@ import {
   TrackerRealtimeGateway,
 } from '@task-stream/web/tracker/domain';
 import {
+  concatMap,
   debounceTime,
   filter,
+  from,
+  last,
   map,
   merge,
   mergeMap,
@@ -100,7 +104,18 @@ export const IssueStore = signalStore(
       activity = inject(ActivityGateway),
       realtime = inject(TrackerRealtimeGateway),
       notifications = inject(Notifications),
+      attachments = inject(AttachmentsGateway),
     ) => {
+      /** One file after another: the ticket's version moves with each. */
+      const uploadAll = (
+        issueId: string,
+        files: File[],
+        commentId: string | null = null,
+      ) =>
+        from(files).pipe(
+          concatMap((file) => attachments.upload(issueId, file, commentId)),
+          last(),
+        );
       const fetchIssue = (idOrKey: string) =>
         issues.issue(idOrKey).pipe(
           retry({
@@ -267,8 +282,48 @@ export const IssueStore = signalStore(
             .pipe(
               mergeMap(({ payload }) =>
                 runCommand(
-                  comments.add(payload.issueId, payload.body),
-                  'Comentario añadido',
+                  comments
+                    .add(payload.issueId, payload.body)
+                    .pipe(
+                      concatMap((comment) =>
+                        payload.files?.length
+                          ? uploadAll(
+                              payload.issueId,
+                              payload.files,
+                              comment.id,
+                            )
+                          : [comment],
+                      ),
+                    ),
+                  payload.files?.length
+                    ? 'Comentario y adjuntos añadidos'
+                    : 'Comentario añadido',
+                  done,
+                  failed,
+                ),
+              ),
+            ),
+          events
+            .on(issuePageEvents.attachRequested)
+            .pipe(
+              mergeMap(({ payload }) =>
+                runCommand(
+                  uploadAll(payload.issueId, payload.files, payload.commentId),
+                  payload.files.length === 1
+                    ? `${payload.files[0].name} adjuntado`
+                    : `${payload.files.length} archivos adjuntados`,
+                  done,
+                  failed,
+                ),
+              ),
+            ),
+          events
+            .on(issuePageEvents.attachmentRemoveRequested)
+            .pipe(
+              mergeMap(({ payload }) =>
+                runCommand(
+                  attachments.remove(payload.issueId, payload.attachmentId),
+                  'Adjunto eliminado',
                   done,
                   failed,
                 ),