feat: Knowledge view + entity types (People, Places, Lists)

Data model:
- Migration 0036: adds note_type TEXT (default 'note') and metadata JSONB
  to the notes table; index on note_type
- Note model: entity_type property, note_type/metadata in to_dict()
- create_note() accepts note_type and metadata params

Backend:
- /api/knowledge — unified paginated endpoint: type/tag/sort/q filters,
  semantic search via embeddings, excludes tasks
- /api/knowledge/tags — distinct tags across knowledge objects
- New LLM tools: create_person, create_place, create_list, add_to_list,
  clear_checked_items — all wired into execute_tool()
- People and places auto-injected as compact summary into LLM system prompt

Frontend:
- KnowledgeView replaces HomeView at /; left filter panel (type+tag),
  toolbar (search, sort, graph toggle), card grid with type-aware cards
  (indigo=note, emerald=person, amber=place, sky=list), load-more pagination
- Today bar: upcoming events, overdue task count, Briefing/Chat links
- Floating mini-chat sticky to bottom: creates/continues a conversation
  inline, message history expands upward, close button ends session
- Graph panel: toggles as a 420px right panel at full viewport width
- AppHeader: Knowledge, Chat, Briefing, Calendar, Tasks, Projects
- Router: / → KnowledgeView; /knowledge redirect; HomeView import removed

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

frontend/src/components/AppHeader.vue

@@ -15,7 +15,8 @@ const chatStore = useChatStore();
 const router = useRouter();
 const route = useRoute();
 
-const isChatActive = computed(() => route.path.startsWith("/chat"));
+const isChatActive = computed(() => route.path.startsWith("/chat"))
+const isKnowledgeActive = computed(() => route.path === "/" || route.path === "/knowledge");
 
 const mobileMenuOpen = ref(false);
 
@@ -72,15 +73,12 @@ router.afterEach(() => {
 
       <!-- Center: primary navigation (desktop) -->
       <div class="nav-center">
-        <router-link to="/notes" class="nav-link">Notes</router-link>
-        <router-link to="/projects" class="nav-link">Projects</router-link>
-        <router-link to="/tasks" class="nav-link">Tasks</router-link>
+        <router-link to="/" class="nav-link" :class="{ 'router-link-active': isKnowledgeActive }">Knowledge</router-link>
         <router-link to="/chat" :class="['nav-link', { 'router-link-active': isChatActive }]">Chat</router-link>
-        <router-link to="/graph" class="nav-link">Graph</router-link>
-        <router-link to="/calendar" class="nav-link">Calendar</router-link>
         <router-link to="/briefing" class="nav-link">Briefing</router-link>
-        <router-link to="/news" class="nav-link">News</router-link>
-        <router-link to="/shared" class="nav-link">Shared</router-link>
+        <router-link to="/calendar" class="nav-link">Calendar</router-link>
+        <router-link to="/tasks" class="nav-link">Tasks</router-link>
+        <router-link to="/projects" class="nav-link">Projects</router-link>
       </div>
 
       <!-- Right: status + utilities + gear + user -->
@@ -123,13 +121,12 @@ router.afterEach(() => {
 
     <!-- Mobile dropdown -->
     <div v-if="mobileMenuOpen" class="mobile-menu">
-      <router-link to="/notes" class="nav-link">Notes</router-link>
-      <router-link to="/projects" class="nav-link">Projects</router-link>
-      <router-link to="/tasks" class="nav-link">Tasks</router-link>
+      <router-link to="/" class="nav-link" :class="{ 'router-link-active': isKnowledgeActive }">Knowledge</router-link>
       <router-link to="/chat" :class="['nav-link', { 'router-link-active': isChatActive }]">Chat</router-link>
-      <router-link to="/graph" class="nav-link">Graph</router-link>
-      <router-link to="/calendar" class="nav-link">Calendar</router-link>
       <router-link to="/briefing" class="nav-link">Briefing</router-link>
+      <router-link to="/calendar" class="nav-link">Calendar</router-link>
+      <router-link to="/tasks" class="nav-link">Tasks</router-link>
+      <router-link to="/projects" class="nav-link">Projects</router-link>
       <router-link to="/news" class="nav-link">News</router-link>
       <router-link to="/shared" class="nav-link">Shared</router-link>
       <div class="mobile-divider"></div>

frontend/src/router/index.ts

@@ -1,5 +1,4 @@
 import { createRouter, createWebHistory } from "vue-router";
-import HomeView from "@/views/HomeView.vue";
 import { useAuthStore } from "@/stores/auth";
 
 const router = createRouter({
@@ -7,8 +6,12 @@ const router = createRouter({
   routes: [
     {
       path: "/",
-      name: "home",
-      component: HomeView,
+      name: "knowledge",
+      component: () => import("@/views/KnowledgeView.vue"),
+    },
+    {
+      path: "/knowledge",
+      redirect: "/",
     },
     {
       path: "/login",