feat: add optional volume descriptions for UI

Added VOLUME_DESCRIPTIONS config dict allowing optional user-friendly
descriptions for volumes shown in management UI.

Changes:
- Added VOLUME_DESCRIPTIONS dict in jupyterhub_config.py (optional, co-defined
  with DOCKER_SPAWNER_VOLUMES)
- Exposed volume_descriptions via c.JupyterHub.template_vars
- Updated home.html to conditionally display descriptions if defined
- If volume not in VOLUME_DESCRIPTIONS, no description shown (UI remains agnostic)

Configuration example:
VOLUME_DESCRIPTIONS = {
    'home': 'User home directory files, configurations',
    'workspace': 'Project files, notebooks, code',
    'cache': 'Temporary files, pip cache, conda cache'
}

Documentation:
- Updated .claude/CLAUDE.md with Manage Volumes implementation details
- Simplified Restart Server section for consistency
- Added template variables to doc/ui-template-customization.md

UI now shows volume name, Docker volume path, and optional description
(if configured). Fully backward compatible - descriptions are optional.

.claude/CLAUDE.md

@@ -258,52 +258,52 @@ The startup script will automatically read this list and create missing groups.
 
 ## User Self-Service Features
 
-The platform provides two self-service features accessible from the user control panel (`/hub/home`):
+### Manage Volumes
 
-### Reset Home Volume
-
-**Purpose**: Allows users to delete their home directory volume and start fresh with a clean environment.
+Selective volume reset allowing users to delete chosen persistent volumes (home, workspace, cache).
 
 **Requirements**:
 - User's JupyterLab server must be stopped
-- Volume `jupyterlab-{username}_home` must exist
+- Volumes dynamically read from `DOCKER_SPAWNER_VOLUMES` config
 
 **Implementation**:
-- API Endpoint: `DELETE /hub/api/users/{username}/reset-home-volume`
-- Handler: `services/jupyterhub/conf/bin/custom_handlers.py::ResetHomeVolumeHandler`
-- Uses Docker API to safely remove the volume
-- Only affects home volume - workspace and cache volumes are preserved
+- API Endpoint: `DELETE /hub/api/users/{username}/manage-volumes`
+- Handler: `services/jupyterhub/conf/bin/custom_handlers.py::ManageVolumesHandler`
+- Template: `services/jupyterhub/templates/home.html` with dynamic checkbox generation
+- Volume list extracted via `get_user_volume_suffixes(DOCKER_SPAWNER_VOLUMES)`
+- Optional descriptions from `VOLUME_DESCRIPTIONS` dict (config file)
+- Validates requested volumes against `USER_VOLUME_SUFFIXES`
 
-**Permissions**:
-- Users can reset their own home volume
-- Admins can reset any user's home volume
-- Enforced via `@admin_or_self` decorator
+**Configuration** (`config/jupyterhub_config.py`):
+```python
+DOCKER_SPAWNER_VOLUMES = {
+    "jupyterlab-{username}_home": "/home",
+    "jupyterlab-{username}_workspace": DOCKER_NOTEBOOK_DIR,
+    "jupyterlab-{username}_cache": "/home/lab/.cache",
+}
+
+VOLUME_DESCRIPTIONS = {
+    'home': 'User home directory files, configurations',
+    'workspace': 'Project files, notebooks, code',
+    'cache': 'Temporary files, pip cache, conda cache'
+}
+```
+
+**Permissions**: Users can manage own volumes, admins can manage any user's volumes
 
 ### Restart Server
 
-**Purpose**: Provides one-click Docker container restart without recreating the container.
+One-click Docker container restart without recreation. Preserves volumes and configuration.
 
-**Requirements**:
-- User's JupyterLab server must be running
-- Container `jupyterlab-{username}` must exist
+**Requirements**: User's JupyterLab server must be running
 
 **Implementation**:
 - API Endpoint: `POST /hub/api/users/{username}/restart-server`
 - Handler: `services/jupyterhub/conf/bin/custom_handlers.py::RestartServerHandler`
 - Uses Docker's native `container.restart(timeout=10)` method
-- Preserves container identity, volumes, and configuration
 - Does NOT recreate container (unlike JupyterHub's stop/spawn cycle)
 
-**Permissions**:
-- Users can restart their own server
-- Admins can restart any user's server
-- Enforced via `@admin_or_self` decorator
-
-**UI Location**:
-- Custom template: `services/jupyterhub/templates/home.html`
-- Reset button visible when server is stopped
-- Restart button visible when server is running
-- Both include confirmation modals with warnings
+**Permissions**: Users can restart own server, admins can restart any user's server
 
 ## Troubleshooting
 

config/jupyterhub_config.py

@@ -120,6 +120,14 @@ DOCKER_SPAWNER_VOLUMES = {
     "jupyterhub_shared": "/mnt/shared" # shared drive across hub
 }
 
+# Optional descriptions for user volumes (shown in UI)
+# If a volume suffix is not listed here, no description will be shown
+VOLUME_DESCRIPTIONS = {
+    'home': 'User home directory files, configurations',
+    'workspace': 'Project files, notebooks, code',
+    'cache': 'Temporary files, pip cache, conda cache'
+}
+
 # Helper function to extract user-specific volume suffixes
 def get_user_volume_suffixes(volumes_dict):
     """Extract volume suffixes from volumes dict that follow jupyterlab-{username}_<suffix> pattern"""
@@ -145,9 +153,10 @@ if c is not None:
     # Set volumes from constant
     c.DockerSpawner.volumes = DOCKER_SPAWNER_VOLUMES
 
-    # Make volume suffixes available to templates
+    # Make volume suffixes and descriptions available to templates
     c.JupyterHub.template_vars = {
-        'user_volume_suffixes': USER_VOLUME_SUFFIXES
+        'user_volume_suffixes': USER_VOLUME_SUFFIXES,
+        'volume_descriptions': VOLUME_DESCRIPTIONS
     }
 
 # Built-in groups that cannot be deleted (auto-recreated if missing)

doc/ui-template-customization.md

@@ -8,6 +8,10 @@ JupyterHub templates extended using Jinja2 to add custom UI features (server res
 - Changes require Docker rebuild with `--no-cache` flag
 - JupyterHub 5.4.2 uses Bootstrap 5 (not Bootstrap 4)
 
+**Template Variables** (via `c.JupyterHub.template_vars`):
+- `user_volume_suffixes`: List of volume suffixes from `DOCKER_SPAWNER_VOLUMES`
+- `volume_descriptions`: Optional dict mapping suffixes to descriptions
+
 **JavaScript Integration**:
 All custom JavaScript wrapped in RequireJS to ensure library loading:
 ```javascript

services/jupyterhub/templates/home.html

@@ -146,6 +146,10 @@
               <strong>{{ volume_suffix }}</strong>
               <br>
               <code class="text-muted">jupyterlab-{{ user.name }}_{{ volume_suffix }}</code>
+              {% if volume_descriptions and volume_suffix in volume_descriptions %}
+              <br>
+              <small class="text-muted">{{ volume_descriptions[volume_suffix] }}</small>
+              {% endif %}
             </label>
           </div>
           {% endfor %}