Per-conv streaming state, immediate message_count commit, auto-new-chat on open

stores/chat.ts:
- Replace 7 global stream refs with convStreams: Record<number, ConvStreamState>
- Each conversation tracks its own stream state; 7 names become computed getters
- Add isStreamingConv(id) public helper
- Increment message_count +2 immediately after POST 202 (not at done) so the
  cleanup watcher never deletes a mid-generation conversation
- SSE reconnect retries now run for background conversations regardless of
  which conv is currently viewed
- error toasts only shown when the erroring conv is currently viewed
- deleteConversation cleans up orphaned stream state

ChatView.vue:
- Remove invalid write to store.lastContextMeta (now a read-only computed)
- Add !store.isStreamingConv(newId) guard to watch(convId) fetch so navigating
  back to a generating conversation shows accumulated content without stale refetch
- Add startNewConversation() helper; opening /chat with no ID auto-creates a
  new conversation and redirects to it (on mount and on navigation)
- Deleting a conversation also auto-creates a new one

Also committing previous-session changes (keyboard nav + task routing):
- App.vue: e shortcut only on note-view (not task-view, which is removed)
- TaskCard.vue: route directly to /tasks/:id (viewer), remove View buttons
- router/index.ts: remove task-view route; /tasks/:id now maps to TaskEditorView
- TasksListView.vue: Enter key pushes to /tasks/:id

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

frontend/src/components/TaskCard.vue

@@ -1,5 +1,4 @@
 <script setup lang="ts">
-import { useRouter } from "vue-router";
 import type { Task, TaskStatus } from "@/types/task";
 import StatusBadge from "@/components/StatusBadge.vue";
 import PriorityBadge from "@/components/PriorityBadge.vue";
@@ -12,7 +11,6 @@ const props = defineProps<{
   compact?: boolean;
   projectTitle?: string;
 }>();
-const router = useRouter();
 const emit = defineEmits<{
   "tag-click": [tag: string];
   "status-toggle": [id: number, status: TaskStatus];
@@ -49,7 +47,7 @@ function isOverdue(): boolean {
 </script>
 
 <template>
-  <router-link :to="`/tasks/${task.id}/edit`" :class="['task-card', { compact }]">
+  <router-link :to="`/tasks/${task.id}`" :class="['task-card', { compact }]">
 
     <!-- Compact: single row -->
     <template v-if="compact">
@@ -64,7 +62,6 @@ function isOverdue(): boolean {
       <span v-if="task.due_date" :class="['due-compact', { overdue: isOverdue() }]">
         {{ task.due_date }}
       </span>
-      <button class="btn-edit-compact" title="View detail" @click.prevent.stop="router.push(`/tasks/${props.task.id}`)">View</button>
     </template>
 
     <!-- Full: original layout -->
@@ -77,7 +74,6 @@ function isOverdue(): boolean {
         />
         <PriorityBadge :priority="task.priority!" />
         <h3 class="task-title">{{ task.title || "Untitled" }}</h3>
-        <button class="btn-edit" title="View detail" @click.prevent.stop="router.push(`/tasks/${props.task.id}`)">View</button>
       </div>
       <div v-if="task.body" class="task-preview prose" v-html="renderPreview(task.body)"></div>
       <div class="task-meta">
@@ -177,26 +173,6 @@ function isOverdue(): boolean {
   color: var(--color-danger, #e74c3c);
   font-weight: 600;
 }
-.btn-edit-compact {
-  flex-shrink: 0;
-  padding: 0.15rem 0.45rem;
-  font-size: 0.75rem;
-  background: none;
-  color: var(--color-text-muted);
-  border: 1px solid var(--color-border);
-  border-radius: var(--radius-sm);
-  cursor: pointer;
-  opacity: 0;
-  transition: opacity 0.15s, color 0.15s;
-}
-.task-card.compact:hover .btn-edit-compact {
-  opacity: 1;
-}
-.btn-edit-compact:hover {
-  color: var(--color-primary);
-  border-color: var(--color-primary);
-}
-
 /* Full layout */
 .task-top {
   display: flex;
@@ -213,21 +189,6 @@ function isOverdue(): boolean {
   text-overflow: ellipsis;
   white-space: nowrap;
 }
-.btn-edit {
-  flex-shrink: 0;
-  padding: 0.25rem 0.6rem;
-  font-size: 0.8rem;
-  background: var(--color-bg-card);
-  color: var(--color-text-secondary);
-  border: 1px solid var(--color-border);
-  border-radius: var(--radius-sm);
-  cursor: pointer;
-  transition: color 0.15s, border-color 0.15s;
-}
-.btn-edit:hover {
-  color: var(--color-primary);
-  border-color: var(--color-primary);
-}
 .task-preview {
   margin: 0 0 0.5rem;
   color: var(--color-text-secondary);