daemon: event.* fan-out (D5) + category.list/queue.list (D3) — GUI-ready

The two items aimed at pointing GUI at a real veloxd instead of mockd.

rpc/event_hub — per-subscription fan-out shared by both transports.
subscribe() registers a connection with no interest; set_filter()
(session.subscribe, replaces not adds) turns on event kinds and an
optional per-task id filter; publish() delivers a pre-built
notification to every matching subscriber. session.subscribe on both
UdsServer and WsServer now does the real thing — registers/updates a
subscription, tears it down in close_conn.

sched/scheduler — the on_engine_state hook now actually publishes:
- transition() is the one place a task's row changes state; it reads
  the store's own prior row for previousState (authoritative
  regardless of engine/scheduler timing), writes the error columns,
  and — when a hub is supplied — publishes event.task.state with
  {taskId, state, previousState, summary, error}. Wired into every
  transition: scheduler-driven (admission -> probing, resume ->
  connecting, pause) and engine-reported (on_engine_state).
- progress_snapshot(): one row per task the engine is tracking
  (EnginePort::progress(), a new interface method backed by
  DownloadHandle::progress()), plus a store side-effect
  (Tasks::update_progress) so download.list/get stay current between
  state transitions. Returns rows; does NOT publish itself — batching
  into one array message is the caller's job, per the schema's
  x-maxRateHz: 4 and AGENT-DAEMON.md item 5 ("one message per task per
  tick burns a core"). main.cpp's 250 ms timerfd is that caller: one
  event.task.progress per tick, only when there's something to say.

dispatcher::on_download_add now publishes event.task.added (schema:
"summary is always present so a client can insert the row without a
follow-up download.get").

store/categories, store/queues — the two D3 handlers GUI's panels
call. category.list projects the six seeded built-ins; queue.list
derives taskIds from tasks.queue_id/queue_position (Queue's own schema
note: a queue's stored row never carries membership, download.update
/ queue.reorder do).

Verified live end to end against tools/testserver: a subscribed client
sees event.task.added on add, then the full event.task.state sequence
(queued -> probing -> connecting -> downloading -> assembling ->
verifying -> complete) with correct previousState at every step, and
real category.list / queue.list results.

Tests: event_hub (filter-by-kind, filter-by-task-id, replace-not-add,
unsubscribe), store_categories_queues, plus new sched_scheduler cases
for event.task.state publishing and progress_snapshot's store
side-effect. 38 daemon/cli tests green; sched_scheduler / event_hub /
ws_server / uds_roundtrip TSan-clean.

deferrals.md: D5 mostly closed (event.task.removed and the
still-unpublished events wait on their owning D3 handlers); D3 down to
the remaining download.* verbs, rules/settings/limiter/schedule,
queue mutation, category mutation, grabber, media.

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01Upd9WhG9oppieig5nRDLig

daemon/src/store/queues.cpp

@@ -0,0 +1,48 @@
+#include "store/queues.hpp"
+
+#include <nlohmann/json.hpp>
+
+namespace velox::daemon::store {
+
+namespace proto = velox::proto;
+
+DbResult<std::vector<proto::Queue>> Queues::list() {
+    auto st = db_.prepare(
+        "SELECT queue_id, name, state, max_concurrent, schedule FROM queues ORDER BY name");
+    if (!st) return std::unexpected(st.error());
+
+    std::vector<proto::Queue> out;
+    for (;;) {
+        auto row = st->step();
+        if (!row) return std::unexpected(row.error());
+        if (!*row) break;
+
+        proto::Queue q;
+        q.queueId = st->column_text(0);
+        q.name = st->column_text(1);
+        if (auto s = proto::parse_QueueState(st->column_text(2))) q.state = *s;
+        q.maxConcurrent = st->column_int(3);
+        if (!st->column_is_null(4)) {
+            auto j = nlohmann::json::parse(st->column_text(4), nullptr, false);
+            if (auto sched = proto::parse<proto::Schedule>(j, "schedule")) q.schedule = *sched;
+        }
+
+        auto ts = db_.prepare(
+            "SELECT task_id FROM tasks WHERE queue_id = ?1 ORDER BY queue_position");
+        if (!ts) return std::unexpected(ts.error());
+        if (auto b = ts->bind(1, std::string_view(q.queueId)); !b) return std::unexpected(b.error());
+        std::vector<std::string> ids;
+        for (;;) {
+            auto r = ts->step();
+            if (!r) return std::unexpected(r.error());
+            if (!*r) break;
+            ids.push_back(ts->column_text(0));
+        }
+        q.taskIds = std::move(ids);
+
+        out.push_back(std::move(q));
+    }
+    return out;
+}
+
+}  // namespace velox::daemon::store