fix(cli): resolve duplicate -f short option conflict in projects list (#11)

## Summary

This PR fixes a duplicate short option (`-f`) conflict in the `projects
list` command.

Previously:
- `--filter` used `-f`
- `--format` also used `-f`

This caused Click/Typer to emit a warning:

> UserWarning: The parameter -f is used more than once. Remove its
duplicate as parameters should be unique.

Now:
- `--filter` uses `-F`
--format keeps `-f` (common CLI convention for format)
No breaking changes for long options.

---

## Testing

- [x] Tested `conviso projects list --help`
- [x] Tested with `--filter`
- [x] Tested with `--format`
- [x] Confirmed warning no longer appears

---

## Before Fix (Warning Example)

![duplicate -f
warning](https://github.com/user-attachments/assets/dc8977ce-da6d-40bd-91ba-02fa9e1657f1)

Author: fhverga

src/conviso/VERSION

@@ -1 +1 @@
-0.2.7
+0.2.8

src/conviso/commands/projects.py

@@ -22,7 +22,7 @@ def list_projects(
     filters: Optional[List[str]] = typer.Option(
         None,
         "--filter",
-        "-f",
+        "-F",
         help="Apply filters in 'field=value' format. Supports aliases (e.g., id=123, name=foo, status=DONE).",
     ),
     sort_by: Optional[str] = typer.Option(