feat: saved board views and richer board filters

The board now filters by text, type, priority and unassigned tickets as
well. Any combination can be saved as a named view, private or shared with
the project, and opened again with one click.

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

libs/web/tracker/domain/src/index.ts

@@ -5,3 +5,4 @@ export * from './lib/models/workflow';
 export * from './lib/ports/gateways';
 export * from './lib/models/mentions';
 export * from './lib/models/hierarchy';
+export * from './lib/models/views';