chore(benchmarks-website): add doc comments to public Rust items

CLAUDE.md requires every public API definition to carry a doc
comment. Sweep the v3 server and migrator for `pub` items that
landed without one and add a one-liner that says what each is for —
no essays. Items touched:

- `vortex-bench-server::api`: GroupsResponse, Group, ChartLink,
  ChartResponse, CommitPoint, HealthResponse, RowCounts (every wire
  shape on the public read API now has a doc).
- `vortex-bench-migrate::lib`: per-`pub mod` summaries on classifier,
  commits, migrate, source, v2, verify.
- `vortex-bench-migrate::v2::V2Person`: author/committer block.
- `vortex-bench-migrate::verify::ChartDiff`: per-group chart-count
  divergence row.

No code changes. `cargo build -p vortex-bench-server -p
vortex-bench-migrate` is clean.

Signed-off-by: Claude <noreply@anthropic.com>

Author: claude

benchmarks-website/migrate/src/lib.rs

@@ -13,9 +13,15 @@
 //! The migrator is throwaway: once v3 cuts over, both the binary and
 //! the classifier go away.
 
+/// Routing v2 records into v3 fact tables, ported from v2's `getGroup`.
 pub mod classifier;
+/// V2 commit -> v3 `commits` row upserts.
 pub mod commits;
+/// End-to-end migration of v2 dumps into a v3 DuckDB.
 pub mod migrate;
+/// Streaming readers for the v2 S3 bucket and local dumps.
 pub mod source;
+/// Wire shapes of the v2 benchmark dataset.
 pub mod v2;
+/// Structural diff between a migrated v3 DuckDB and v2's `/api/metadata`.
 pub mod verify;

benchmarks-website/migrate/src/v2.rs

@@ -137,6 +137,7 @@ pub struct V2Commit {
     pub url: Option<String>,
 }
 
+/// Author or committer block on a v2 commit record.
 #[derive(Debug, Clone, Deserialize)]
 pub struct V2Person {
     #[serde(default)]

benchmarks-website/migrate/src/verify.rs

@@ -30,6 +30,8 @@ pub struct VerifyReport {
     pub chart_diffs: Vec<ChartDiff>,
 }
 
+/// One group's chart-count divergence between v2 and v3, captured when the
+/// group is structurally present on both sides but the counts differ.
 #[derive(Debug, Clone)]
 pub struct ChartDiff {
     pub group: String,

benchmarks-website/server/src/api.rs

@@ -162,11 +162,14 @@ impl ChartQuery {
     }
 }
 
+/// Body of `GET /api/groups`: every group with its chart links and summary.
 #[derive(Debug, Serialize)]
 pub struct GroupsResponse {
     pub groups: Vec<Group>,
 }
 
+/// One group: a display name, a slug for the group permalink, and the chart
+/// links inside it. Optionally carries a v2-compatible rollup summary.
 #[derive(Debug, Serialize)]
 pub struct Group {
     pub name: String,
@@ -268,12 +271,16 @@ pub struct NamedChartResponse {
     pub chart: ChartResponse,
 }
 
+/// One chart's short label inside a group (e.g. `Q1`) plus the slug that
+/// resolves to its `/api/chart/{slug}` payload.
 #[derive(Debug, Serialize)]
 pub struct ChartLink {
     pub name: String,
     pub slug: String,
 }
 
+/// Body of `GET /api/chart/{slug}`: every commit with data, every series'
+/// values aligned to those commits, and per-series engine/format tags.
 #[derive(Debug, Clone, Serialize)]
 pub struct ChartResponse {
     pub display_name: String,
@@ -311,6 +318,8 @@ pub struct FilterUniverse {
     pub formats: Vec<String>,
 }
 
+/// One row of the `commits[]` array on a [`ChartResponse`]. Carries enough
+/// metadata for the tooltip and the click-to-PR handler in `chart-init.js`.
 #[derive(Debug, Clone, Serialize)]
 pub struct CommitPoint {
     pub sha: String,
@@ -319,6 +328,8 @@ pub struct CommitPoint {
     pub url: String,
 }
 
+/// Body of `GET /health`: liveness probe plus a row-count rollup that's
+/// useful for "did my ingest land?" smoke tests.
 #[derive(Debug, Serialize)]
 pub struct HealthResponse {
     pub status: &'static str,
@@ -328,6 +339,7 @@ pub struct HealthResponse {
     pub row_counts: RowCounts,
 }
 
+/// Per-fact-table row counts surfaced by `/health`.
 #[derive(Debug, Serialize)]
 pub struct RowCounts {
     pub commits: i64,