fix(kernel,server,workflow): per-stage retry budget, sane freestyle budget, tail /events

Three defects surfaced by a live headless freestyle_planning run (all made a
long execution workflow fail or stall in ways invisible to a REST operator):

1. retryCount was session-global (DefaultOrchestrationReducer): TransitionExecuted
   updated currentStageId but never reset retryCount, while shouldRetry gates on
   it per-stage. An early stage that burned its 3 retries starved every later
   stage of its own — the next stage's first *retryable* failure went terminal.
   Reset retryCount on stage entry; back-edge loops stay bounded by the separate
   refinementIterations counter. Regression test added.

2. Freestyle stages ran at StageConfig's 4096-token default (ExecutionPlanCompiler
   never set a budget) vs 16384-32768 for static role_pipeline stages. A tool-heavy
   stage truncated its context every round, evicting the file_read results it just
   gathered, so it re-read forever and never accumulated enough to write. Set 16384.

3. GET /events returned the OLDEST `limit` events (readFrom(0) then take): for a
   session past `limit` events the tail — including a pending ApprovalRequested —
   was invisible to a headless/REST poller, the exact caller POST /approve serves.
   Default now tails; explicit fromSeq still paginates forward.

apps/server/src/main/kotlin/com/correx/apps/server/routes/SessionRoutes.kt

@@ -199,10 +199,11 @@ private fun Route.getEventsRoute(module: ServerModule) {
     get("/events") {
         val id = call.parameters["id"]
             ?: return@get call.respond(HttpStatusCode.BadRequest, "Missing session id")
-        val fromSeq = call.request.queryParameters["fromSeq"]?.toLongOrNull() ?: 0L
+        val fromSeqParam = call.request.queryParameters["fromSeq"]?.toLongOrNull()
+        val fromSeq = fromSeqParam ?: 0L
         val limit = call.request.queryParameters["limit"]?.toIntOrNull() ?: DEFAULT_EVENT_LIMIT
         val typeFilter = call.request.queryParameters["type"]
-        val rows = module.eventStore.readFrom(TypeId(id), fromSeq)
+        val mapped = module.eventStore.readFrom(TypeId(id), fromSeq)
             .asSequence()
             .map { stored ->
                 val payloadJson = eventJson.encodeToJsonElement(EventPayload.serializer(), stored.payload)
@@ -218,8 +219,12 @@ private fun Route.getEventsRoute(module: ServerModule) {
                 )
             }
             .filter { typeFilter == null || it.type == typeFilter }
-            .take(limit)
             .toList()
+        // No explicit fromSeq = a "what's happening now" tail: return the most recent `limit` events
+        // (a pending ApprovalRequested lives at the tail, so the oldest-200 default hid it from a
+        // headless/REST operator — the very caller POST /approve exists to serve). Explicit fromSeq
+        // keeps forward, ascending pagination from that point.
+        val rows = if (fromSeqParam == null) mapped.takeLast(limit) else mapped.take(limit)
         call.respond(rows)
     }
 }