feat(ui): add /dash route, shared nav, project dashboard with /v1/projects API

Restructure routes: / and /dash show a project overview dashboard,
/activity hosts the existing timeline, /cv remains. Shared Layout
component provides consistent nav header and footer across all routes.

New /v1/projects endpoint aggregates per-repo activity stats (commits,
issues, PRs, date range) from existing event data via SQL. Dashboard
ranks projects by weighted recency + volume score and renders a card
grid.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/pages/CvPage.tsx

@@ -3,7 +3,6 @@ import { useLocation } from 'react-router-dom';
 import { useQuery } from '@tanstack/react-query';
 import Alert from 'react-bootstrap/Alert';
 import Col from 'react-bootstrap/Col';
-import Container from 'react-bootstrap/Container';
 import Row from 'react-bootstrap/Row';
 import Spinner from 'react-bootstrap/Spinner';
 
@@ -34,13 +33,13 @@ export function CvPage() {
 
   if (cvQ.isLoading) {
     return (
-      <Container className="py-4">
+      <>
         <CvHeader />
         <div className="d-flex align-items-center gap-2">
           <Spinner animation="border" role="status" size="sm" />
           <span>loading cv…</span>
         </div>
-      </Container>
+      </>
     );
   }
 
@@ -50,7 +49,7 @@ export function CvPage() {
       ? ' (github limits unauthenticated requests to 60/hour per ip — try again shortly)'
       : '';
     return (
-      <Container className="py-4">
+      <>
         <CvHeader />
         <Alert variant="danger">
           <Alert.Heading>cv unavailable</Alert.Heading>
@@ -62,7 +61,7 @@ export function CvPage() {
             retry
           </button>
         </Alert>
-      </Container>
+      </>
     );
   }
 
@@ -72,15 +71,15 @@ export function CvPage() {
 
   if (bodySections.length === 0 && navSections.length === 0) {
     return (
-      <Container className="py-4">
+      <>
         <CvHeader />
         <Alert variant="warning">cv unavailable: no sections in config</Alert>
-      </Container>
+      </>
     );
   }
 
   return (
-    <Container className="py-4">
+    <>
       <CvHeader />
       <Row>
         <Col lg={9} className="cv-body">
@@ -103,6 +102,6 @@ export function CvPage() {
           <CvTimeline data={data} />
         </Col>
       </Row>
-    </Container>
+    </>
   );
 }