The filter regex pattern was not matching values inside parentheses correctly.
The lookahead pattern only allowed `&&`, `||`, or end-of-string after filter
values, but when filters are wrapped in parentheses like `( project = Filtertest )`,
the closing `)` appears after the value.
Fixed by adding `\)` to the lookahead pattern so it correctly handles closing
parentheses. This allows the project filter (and other filters) to work
properly when nested in parentheses.
- Added tests for project filters in parentheses (both frontend and backend)
- Backend tests confirm the backend already handled this correctly
- Frontend regex pattern now matches the backend behavior
Fixes#1645
c8837aeaeb