feat: steadier live updates and notices for public proposals

- The web pings the live connection, reconnects when it goes quiet and
  reloads what each screen shows after reconnecting.
- Dropping a card on a column it cannot go to puts it back.
- Owners and admins get a notice when a proposal arrives.
- The proposal limit lives in Redis, so it holds across instances.
- REST tells whether I voted; pasted images leave the attachment list.
- Deleting a project removes its Git integration; no lint warnings left.
- Reactions and the blocked badge are components of their own.
- Docs: what is done and what is left (chapter 10), Word and PDF.

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

libs/api/tracker/presenters/src/lib/http/dto/responses.dto.ts

@@ -443,6 +443,10 @@ export class IssueDto {
   })
   blockedBy!: IssueParentDto[];
   @ApiProperty({ description: 'How many want it done' }) votes!: number;
+  @ApiProperty({
+    description: 'Whether I voted for it (false without a token)',
+  })
+  voted!: boolean;
   @ApiProperty({
     description:
       'Place in the backlog and its board column (ascending, as text)',