docs(backlog): record llama-probe registration (64a90e7) + event-store probe in RETRO

A§4 LLAMA_SERVER probe is now registered (gated on a llamacpp provider URL); EVENT_STORE
latency probe was already wired (266bbf0). Both move to RETRO. Remaining A§4: tokens/sec
throughput feed (health endpoint is reachability-only) + live health TUI pane.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

BACKLOG.md

@@ -28,7 +28,7 @@ matching bullets below are superseded; only the noted follow-ups remain live:
 
 - **G** turnId `/repo`↔`/repo2` collision + WorkspaceStateProbe newline fingerprint — `784accb`
 - **I** `.cs`/Godot-Mono symbols — `f715ffa`; structural `.tscn`/`.tres` validator — `0e251d6`
-- **A §4** EventStore latency probe (wired) + llama-server probe — `266bbf0` *(follow-up: llama probe live wiring)*
+- **A §4** EventStore latency probe (wired) + llama-server probe — `266bbf0`, **registered** `64a90e7` (gated on a configured `llamacpp` provider URL)
 - **B §6 + C-A3** `CritiqueFinding` type + calibration projection — `f783eed` *(follow-up: `CritiqueOutcomeCorrelatedEvent` producer)*
 - **C-A1** brief echo-back gate — `1df7af5` *(follow-up: `planner.md` brief_echo + `role_pipeline` metadata to activate)*
 - **C-A2** stage-level plan checkpointing — `1a1b5cc`
@@ -51,9 +51,12 @@ matching bullets below are superseded; only the noted follow-ups remain live:
 Metrics + CLI + TUI pane and the health backbone are shipped (fe94140, 4f6bfa8,
 f8fd260) — those are RETRO candidates once live-QA'd. Remaining:
 
-- [ ] **§4 LLAMA_SERVER health probe** — liveness + tokens/sec degradation trend
-      (session-scoped, needs HTTP). Same `HealthProbe` framework as the shipped disk probe.
-- [ ] **§4 EVENT_STORE health probe** — append + fsync latency heartbeat.
+- [x] **§4 LLAMA_SERVER health probe** — `266bbf0` (probe) + `64a90e7` (registered in the health
+      monitor, gated on a `llamacpp` provider URL, via `HttpLlamaLivenessClient`). Liveness is live;
+      tokens/sec degradation needs a throughput feed (the `/health` endpoint is reachability-only) —
+      that remainder noted in RETRO. → RETRO.
+- [x] **§4 EVENT_STORE health probe** — append + fsync latency heartbeat. `266bbf0`
+      (`EventStoreLatencyProbe.forStore`, wired into the health monitor). → RETRO.
 - [ ] **§4/§3 live health TUI pane** — deferred to follow the metrics cadence
       (projection + CLI first, then pane). `correx health` CLI already exists.
 - [ ] **§3 tier-2 stats** — full session-completion summary pane polish (basic pane shipped).