Simulator: h_launch_app accepts unknown app names silently

[jeffory]

Problem

h_launch_app in simulator/sim_socket_handler.c (~line 396) queues the requested app name and unconditionally returns {"ok": true}. The actual lookup happens later, on the OS poll loop, via launcher_launch_by_name(). If the name doesn't match anything in s_apps[], that lookup silently no-ops — but the RPC caller has already been told the launch succeeded.

static char *h_launch_app(const char *params) {
    char name[128] = {0};
    json_get_str(params, "name", name, sizeof(name));
    if (!name[0]) {
        return strdup("{\"jsonrpc\":\"2.0\",\"error\":{\"code\":-32602,\"message\":\"name required\"}}");
    }
    s_pending_launch = strdup(name);
    static char buf[256];
    snprintf(buf, sizeof(buf),
             "{\"jsonrpc\":\"2.0\",\"result\":{\"ok\":true,\"app_name\":\"%s\"}}", name);
    return strdup(buf);
}

Compounding this: scan_apps() (src/os/launcher.c) runs once at boot. Any app staged onto the SD card after the simulator process has already started is invisible to the launcher for the lifetime of that process — while launch_app still reports success.

Impact

This cost real debugging time during e2e test development: a launch RPC would report ok: true and the test would then wait/poll for behavior that could never happen, with no error signal pointing at the actual cause (stale app list / typo'd app name).

Suggested direction

• Validate the requested name against s_apps[] in h_launch_app (or at the point s_pending_launch is consumed) and return an RPC error if it isn't found.
• Consider adding an RPC to trigger scan_apps() again, so tests don't need to restart the simulator after staging a new app onto the SD image.

Context

Surfaced while implementing Stage 0/1 of the C-Dogs asset-memory redesign (local specs, not tracked in this repo). Parent commits e9b1622e..21a9b389.