AI Implementation feature(910): Scoreboard: Ranking, Matrix, Event Log and Score Graph 1.00 (#53)

docs/guides/scoreboard-page.md

@@ -3,7 +3,7 @@ type: guide
 title: Scoreboard Page
 description: How a signed-in player navigates /scoreboard, uses the four tabs (Ranking, Matrix, Event Log, Score Graph), and watches live solve updates arriving over the authenticated SSE stream.
 tags: [guide, scoreboard, sse, live, ranking, matrix, event-log, score-graph, tester]
-timestamp: 2026-07-23T05:10:00Z
+timestamp: 2026-07-23T05:41:00Z
 ---
 
 # Overview
@@ -157,7 +157,12 @@ The same `solve` frame that lights up the
   New players are appended to the matrix row list.
 * **Event Log**: a new `EventLogRow` is prepended to the list
   (deduplicated by `solveId` so reconnects don't duplicate) and the
-  list is capped at 200.
+  list is capped at 200. The SSE solve frame carries
+  `challenge_name` / `category_abbreviation` (sourced from the same
+  `challenge` + `category` join that backs the
+  `/api/v1/scoreboard/event-log` REST projection), so the prepended
+  row's category abbreviation and challenge name are populated
+  immediately — no refresh is required.
 * **Score Graph**: the matching player's series receives a new
   `{tUtc: awardedAtUtc, value: prevValue + awardedPoints}` point,
   the series list is re-sorted by final value DESC and trimmed to the

docs/guides/scoreboard-stream.md

@@ -3,7 +3,7 @@ type: guide
 title: Scoreboard Stream
 description: How fresh solves are broadcast to clients — both the public unauthenticated scoreboard SSE stream and the authenticated combined /api/v1/events stream that the /scoreboard page consumes.
 tags: [guide, scoreboard, sse, stream, public, authenticated]
-timestamp: 2026-07-23T05:10:00Z
+timestamp: 2026-07-23T05:41:00Z
 ---
 
 # Overview
@@ -43,9 +43,15 @@ is published to the scoreboard hub.
    * `/api/v1/scoreboard/stream` emits a flattened shape
      (`challengeId`, `userId`, `pointsAwarded`, `rankBonus`,
      `solvedAt`) for anonymous spectators.
-   * `/api/v1/events` emits a richer `SolveEventPayload` (with both
-     snake_case and camelCase aliases, plus `position`,
-     `live_points`, `solve_count`, etc.) for the authenticated SPA.
+    * `/api/v1/events` emits a richer `SolveEventPayload` (with both
+      snake_case and camelCase aliases, plus `challenge_name`,
+      `category_abbreviation`, `position`, `live_points`,
+      `solve_count`, etc.) for the authenticated SPA. The display
+      metadata fields are sourced from the same `challenge` +
+      `category` join that backs the `/api/v1/scoreboard/event-log`
+      REST projection, so the Event Log tab can render an SSE-pushed
+      row with the challenge name and category abbreviation without a
+      second lookup.
 
 The hub is in-process; multi-replica deployments need a shared
 pub/sub to fan out across pods (not in scope for this repo).