UI polish: hover lift, skeleton loaders, empty states, badge contrast, transitions

Card & row interactions:
- NoteCard, TaskCard, ProjectCard: translateY(-2px) lift on hover + extended transitions
- Kanban task cards (ProjectView), note rows: same lift treatment
- Task rows in flat/grouped list: soft indigo bg tint on hover
- Chat conversation items: left-border accent + bg tint on hover (was border-only)
- HomeView project mini-cards: translateY(-2px) lift on hover

Global feedback:
- Buttons: scale(0.97) on :active press (theme.css, :not(:disabled) scoped)
- TagPill: color → primary + indigo bg tint on hover
- StatusBadge: increased opacity 15% → 22% + stronger text color for readability

Loading & empty states:
- TasksListView: shimmer skeleton loader (6 rows) + rich empty state with CTA
- ProjectListView: shimmer skeleton cards (4) + rich empty state with CTA
- HomeView: section-empty messages for overdue/high-priority/notes sections
- ProjectView kanban columns: dashed-border styled empty state

Transitions & graph:
- WorkspaceView panels: panel-fade opacity transition on show/hide (v-if inner wrap)
- GraphView D3 nodes: grow to r*1.3 + bold label on mouseover (150ms transition)
- Milestone action buttons: base opacity 0 → 0.35 for discoverability

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/views/WorkspaceView.vue

@@ -261,11 +261,15 @@ onUnmounted(async () => {
 
       <!-- Left: Tasks -->
       <div v-show="panelOpen.tasks" class="ws-panel">
-        <WorkspaceTaskPanel
-          v-if="project"
-          ref="taskPanelRef"
-          :project-id="project.id"
-        />
+        <Transition name="panel-fade">
+          <div v-if="panelOpen.tasks" class="panel-inner">
+            <WorkspaceTaskPanel
+              v-if="project"
+              ref="taskPanelRef"
+              :project-id="project.id"
+            />
+          </div>
+        </Transition>
       </div>
 
       <!-- Center: Chat -->
@@ -376,11 +380,15 @@ onUnmounted(async () => {
 
       <!-- Right: Note Editor -->
       <div v-show="panelOpen.notes" class="ws-panel">
-        <WorkspaceNoteEditor
-          v-if="project"
-          :project-id="project.id"
-          :active-note-id="activeNoteId"
-        />
+        <Transition name="panel-fade">
+          <div v-if="panelOpen.notes" class="panel-inner">
+            <WorkspaceNoteEditor
+              v-if="project"
+              :project-id="project.id"
+              :active-note-id="activeNoteId"
+            />
+          </div>
+        </Transition>
       </div>
 
     </div>
@@ -461,6 +469,21 @@ onUnmounted(async () => {
   min-width: 0;
 }
 
+.panel-inner {
+  height: 100%;
+  display: flex;
+  flex-direction: column;
+}
+
+.panel-fade-enter-active,
+.panel-fade-leave-active {
+  transition: opacity 0.18s ease;
+}
+.panel-fade-enter-from,
+.panel-fade-leave-to {
+  opacity: 0;
+}
+
 /* Chat panel */
 .ws-chat-panel {
   display: flex;