What does this PR do?

list_profiles_on_disk() in kanban_db.py hardcodes Path.home() / ".hermes" / "profiles",
so hermes kanban init always reports "No profiles found" on custom-root deployments
(e.g. Docker with HERMES_HOME=/opt/data), even when valid profiles exist under
$HERMES_HOME/profiles/.

This PR switches list_profiles_on_disk() to use get_default_hermes_root(),
making profile discovery consistent with how kanban_db_path() and workspaces_root()
were fixed in #18985.

Related Issue

Fixes #19017
Related to #18442, #18985

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)

Changes Made

• hermes_cli/kanban_db.py: replace Path.home() / ".hermes" / "profiles" with
  get_default_hermes_root() / "profiles" in list_profiles_on_disk()
• tests/hermes_cli/test_kanban_core_functionality.py: add
  monkeypatch.delenv("HERMES_HOME", raising=False) to existing test, and add
  new test_list_profiles_on_disk_custom_root to cover custom HERMES_HOME case

How to Test

1. Create a fresh directory with a profile under a custom root:

   mkdir hermes-test && cd hermes-test
   mkdir -p data/profiles/my-agent
   echo "model: {}" > data/profiles/my-agent/config.yaml

2. Run kanban init with Docker:

   docker run --rm
   -e HERMES_HOME=/data
   -v $(pwd)/data:/data
   nousresearch/hermes-agent
   hermes kanban init

3. Expected output includes:

   Discovered 1 profile(s) on disk; any of these can be an --assignee:
   my-agent

   Before this fix, the output was:
   "No profiles found under ~/.hermes/profiles."

Checklist

Code

• I've read the Contributing Guide
• My commit messages follow Conventional Commits (fix(scope):, feat(scope):, etc.)
• I searched for existing PRs to make sure this isn't a duplicate
• My PR contains only changes related to this fix/feature (no unrelated commits)
• I've run pytest tests/ -q and all tests pass
• I've added tests for my changes (required for bug fixes, strongly encouraged for features)
• I've tested on my platform: macOS 15.6.1

Documentation & Housekeeping

All N/A