feat: add agent lineage visualization with SVG tree rendering

Add a dedicated /lineage route with custom SVG-based tree visualization
of the agent spawn chain. Nodes are colored by agent type (orchestrator,
researcher, coder, sysadmin, assistant) and display agent ID, type, and
spawn depth. Clicking a node opens a detail panel. Uses sample data
since the API does not yet expose lineage information.

Closes #15

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

src/routes/lineage/+page.ts

@@ -0,0 +1,2 @@
+export const prerender = false;
+export const ssr = false;