sync: bug fixes + eval system from private repo

- Fix chunk_status: pass chunk_status/chunk/metadata to context builder
- Fix vector search: scope by node_id BEFORE similarity search
- Add eval logging system (RAH_EVALS_LOG=1)
- Add eval dashboard at /evals
- Add vitest for testing

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/evals/types.ts

@@ -0,0 +1,29 @@
+export type ScenarioExpectations = {
+  toolsCalled?: string[];
+  toolsCalledSoft?: string[];
+  responseContains?: string[];
+  responseContainsSoft?: string[];
+  responseNotContains?: string[];
+  maxLatencyMs?: number;
+};
+
+export type ScenarioInput = {
+  message: string;
+  focusedNodeId?: number;
+  focusedNodeQuery?: {
+    titleContains?: string;
+    titleEquals?: string;
+  };
+  mode?: 'easy' | 'hard';
+};
+
+export type Scenario = {
+  id: string;
+  name: string;
+  input: ScenarioInput;
+  expect?: ScenarioExpectations;
+  description?: string;
+  tools?: string[];
+  enabled?: boolean;
+  notes?: string;
+};