feat(monitor): Monitor tab as primary landing + errors KPI + recent executions + date filter

Rebrand "Claude Usage" tab to "Monitor" and promote it to first/default tab in
the main TabBar. Monitor is the landing for the reactive loop (construir →
ejecutar → recopilar → analizar → mejorar).

UI additions:
- Local toolbar inside Monitor with date preset combo (1h / 24h / 7d / 30d /
  All), manual Refresh button, and live LED + last-event-ts indicator.
- 5 KPI cards (was 4): added "Errors" derived from COUNT(*) FROM calls WHERE
  success = 0 filtered by the active window.
- New sub-tab "Recent Executions" (first sub-tab) with columns: When,
  Function, Tool, ms, OK (check/X colored), Error class. Backed by calls
  table, sorted by ts DESC, limit 100, filtered by window.
- Violations sub-tab gains "When" column with formatted ts.

Data layer:
- data.h: RecentExecutionRow + window_secs + ws_connected/last_event_ts /
  last_seen_call_id watermark on ClaudeUsageData.
- data_http.{h,cpp}: load_claude_usage_http now takes window_secs and embeds
  ts_filter() in calls/errors/violations queries. total_errors populated.
  recent_executions populated up to 100 rows. New standalone
  load_recent_executions_http() for future WS-driven partial refetch.
- main.cpp: reload_data preserves window_secs across reloads; new
  reload_monitor() does a Monitor-only refetch when the user changes the
  window or clicks Refresh, without re-querying the full registry.

Wiring:
- views.h: draw_monitor + monitor_consume_reload_request() +
  monitor_set_ws_state() exported. draw_claude_usage removed.
- views.cpp: render() consumes monitor_consume_reload_request each frame
  and dispatches reload_monitor().

This is the UI half of issue 0086. The server-side WebSocket endpoint in
sqlite_api and the C++ WS client are next; the LED is wired to
monitor_set_ws_state but stays gray until those land.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

data_http.h

@@ -35,6 +35,28 @@ bool load_unit_tests_http(const std::string& api_url,
                           const std::string& function_id,
                           std::vector<UnitTestRow>& out);
 
+// Issue 0085d: Load Claude usage telemetry from ops:call_monitor (top
+// functions, recent violations, copied code). Si la BD no esta disponible
+// setea out.claude.available = false sin error.
+//
+// `window_secs`: ventana hacia atras desde now. 0 = sin filtro (All).
+// Aplica a total_calls, total_errors, top_functions, recent_executions,
+// recent_violations. total_versions/total_copies son acumulados (no filtran).
+bool load_claude_usage_http(const std::string& api_url, RegistryData& out,
+                            int window_secs);
+
+// Variante legacy (window default 24h). Usar la version con window_secs.
+inline bool load_claude_usage_http(const std::string& api_url, RegistryData& out) {
+    return load_claude_usage_http(api_url, out, 86400);
+}
+
+// Carga la ventana de "Recent Executions" (calls table) ordenada por ts DESC.
+// Filtrada por window_secs (0 = sin filtro). limit = max filas (default 100).
+bool load_recent_executions_http(const std::string& api_url,
+                                 int window_secs, int limit,
+                                 std::vector<RecentExecutionRow>& out,
+                                 long long& out_max_id);
+
 // Operaciones de mutacion (thread-safe porque http_post ya lo es).
 // Devuelven el body de respuesta en `out_body`. true si HTTP status 2xx.
 bool http_post_reindex(const std::string& api_url, std::string& out_body);