fix(furtka): point DEFAULT_BUNDLED_APPS_DIR at /opt/furtka/current/apps

Third install-path miss from the versioned-layout refactor: the bundled
apps moved from /opt/furtka/apps (flat) to
/opt/furtka/versions/<ver>/apps/, reached through the /opt/furtka/current
symlink. paths.py was still pointing at the flat path, so _list_bundled
walked a non-existent directory and /api/bundled returned [] — the
fileshare tile never showed up on /apps.

Tests already use FURTKA_BUNDLED_APPS_DIR env override so nothing in
the suite needed to change. Confirmed on the VM: compat symlink
/opt/furtka/apps -> current/apps makes /api/bundled return the
fileshare manifest immediately, no service restart needed since
scanner.py reads the directory on every request.

Locking the path at current/apps rather than leaving the flat fallback
is deliberate — Phase-2 self-updates flip the symlink, and a flat
/opt/furtka/apps wouldn't move with them; bundled apps would freeze
at whatever version installed first.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

furtka/paths.py

@@ -2,7 +2,11 @@ import os
 from pathlib import Path
 
 DEFAULT_APPS_DIR = Path("/var/lib/furtka/apps")
-DEFAULT_BUNDLED_APPS_DIR = Path("/opt/furtka/apps")
+# Bundled apps live alongside the Python package inside each versioned slot
+# (/opt/furtka/versions/<ver>/apps/), reached via the /opt/furtka/current
+# symlink. A flat /opt/furtka/apps path would break the Phase-2 self-update
+# flow (symlink swap wouldn't move the bundled-app tree along with the code).
+DEFAULT_BUNDLED_APPS_DIR = Path("/opt/furtka/current/apps")
 
 
 def apps_dir() -> Path: