Route task card clicks to edit view; repurpose button as View

Clicking a task card now goes directly to the edit view since that's
the primary use case. The hover button (compact) and button (full card)
are now labeled "View" and link to the detail/viewer view instead.
Sub-task links in TaskViewerView also route to edit.

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

frontend/src/views/TaskViewerView.vue

@@ -282,7 +282,7 @@ const subTaskProgress = computed(() => {
                 :title="`${sub.status} — click to advance`"
                 @click="cycleSubTaskStatus(sub)"
               ></button>
-              <router-link :to="`/tasks/${sub.id}`" class="sub-title" :class="{ 'sub-done': sub.status === 'done' }">
+              <router-link :to="`/tasks/${sub.id}/edit`" class="sub-title" :class="{ 'sub-done': sub.status === 'done' }">
                 {{ sub.title || "Untitled" }}
               </router-link>
               <span v-if="sub.due_date" class="sub-due">{{ sub.due_date }}</span>