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/views/ChatView.vue

@@ -85,8 +85,12 @@ const inputPlaceholder = computed(() => {
 onMounted(async () => {
   document.addEventListener("keydown", onGlobalKeydown);
   await store.fetchConversations();
-  if (convId.value && store.currentConversation?.id !== convId.value) {
-    await store.fetchConversation(convId.value);
+  if (convId.value) {
+    if (store.currentConversation?.id !== convId.value) {
+      await store.fetchConversation(convId.value);
+    }
+  } else {
+    await startNewConversation();
   }
   nextTick(() => inputEl.value?.focus());
 });
@@ -106,16 +110,15 @@ watch(convId, async (newId) => {
   suggestedNotes.value = [];
   autoInjectedNotes.value = [];
   excludedNoteIds.value = [];
-  store.lastContextMeta = null;
   if (newId) {
-    // Skip re-fetch if this conversation is already loaded (avoids race
-    // condition where a stale GET overwrites messages during streaming)
-    if (store.currentConversation?.id !== newId) {
+    // Skip re-fetch if this conversation is already loaded or still streaming
+    // (avoids a stale GET overwriting in-progress messages)
+    if (store.currentConversation?.id !== newId && !store.isStreamingConv(newId)) {
       await store.fetchConversation(newId);
     }
     scrollToBottom();
   } else {
-    store.currentConversation = null;
+    await startNewConversation();
   }
   nextTick(() => inputEl.value?.focus());
 });
@@ -177,10 +180,14 @@ async function selectConversation(id: number) {
   router.push(`/chat/${id}`);
 }
 
-async function newConversation() {
+async function startNewConversation() {
   const conv = await store.createConversation();
-  await store.fetchConversation(conv.id);
   router.push(`/chat/${conv.id}`);
+  // watch(convId) will fire and fetch the conversation
+}
+
+async function newConversation() {
+  await startNewConversation();
 }
 
 async function removeConversation(id: number) {

frontend/src/views/TasksListView.vue

@@ -39,7 +39,7 @@ function onKeydown(e: KeyboardEvent) {
     document.querySelector(".kb-active-item")?.scrollIntoView({ block: "nearest" });
   } else if (e.key === "Enter" && activeIndex.value >= 0) {
     const task = store.tasks[activeIndex.value];
-    if (task) router.push(`/tasks/${task.id}/edit`);
+    if (task) router.push(`/tasks/${task.id}`);
   }
 }