fix: stabilize test suite and repair frontend/backend wiring

- meshcore pin >=2.3.0 (EventType.STATS_CORE floor); setup.sh derives
  optional packages from requirements.txt; Python 3.10 warning
- agent-mode wifi clients proxy route + bare-array response handling
- remove dead AIS/ACARS/VDL2 SPA wiring and orphaned partials/CSS
- agent TLE download to data/tle/ (was littering repo root as gp.php)
- gate deferred background init off under pytest (mock-pollution race)
- complete Popen mocks (context manager protocol, communicate tuples)
- real pipe fds in weather-sat decoder tests (fd 10/11 collision caused
  10s SQLite stalls); satellite tests no longer rewrite data/satellites.py
- register 'live' pytest marker, excluded by default
- update stale test assertions to current APIs

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

static/css/modes/acars.css

@@ -1,115 +0,0 @@
-/* ACARS Sidebar Styles */
-@keyframes pulse {
-    0%, 100% { opacity: 0.3; transform: scale(0.8); }
-    50% { opacity: 1; transform: scale(1); }
-}
-
-/* Main ACARS Sidebar (Collapsible) */
-.main-acars-sidebar {
-    display: flex;
-    flex-direction: row;
-    background: var(--bg-panel);
-    border-left: 1px solid var(--border-color);
-}
-.main-acars-collapse-btn {
-    width: 24px;
-    min-width: 24px;
-    background: rgba(0,0,0,0.4);
-    border: none;
-    border-right: 1px solid var(--border-color);
-    color: var(--accent-cyan);
-    cursor: pointer;
-    display: flex;
-    flex-direction: column;
-    align-items: center;
-    justify-content: center;
-    gap: 5px;
-    padding: 6px 0;
-    transition: background 0.2s;
-}
-.main-acars-collapse-btn:hover {
-    background: rgba(var(--accent-cyan-rgb), 0.15);
-}
-.main-acars-collapse-label {
-    writing-mode: vertical-rl;
-    text-orientation: mixed;
-    font-size: 8px;
-    font-weight: 600;
-    letter-spacing: 1px;
-}
-.main-acars-sidebar.collapsed .main-acars-collapse-label { display: block; }
-.main-acars-sidebar:not(.collapsed) .main-acars-collapse-label { display: none; }
-#mainAcarsCollapseIcon {
-    font-size: 10px;
-    transition: transform 0.3s;
-}
-.main-acars-sidebar.collapsed #mainAcarsCollapseIcon {
-    transform: rotate(180deg);
-}
-.main-acars-content {
-    width: 196px;
-    display: flex;
-    flex-direction: column;
-    overflow: hidden;
-    transition: width 0.3s ease, opacity 0.2s ease;
-}
-.main-acars-sidebar.collapsed .main-acars-content {
-    width: 0;
-    opacity: 0;
-    pointer-events: none;
-}
-.main-acars-messages {
-    max-height: 350px;
-}
-.main-acars-msg {
-    padding: 6px 8px;
-    border-bottom: 1px solid var(--border-color);
-    animation: fadeInMsg 0.3s ease;
-}
-.main-acars-msg:hover {
-    background: rgba(var(--accent-cyan-rgb), 0.05);
-}
-@keyframes fadeInMsg {
-    from { opacity: 0; transform: translateY(-3px); }
-    to { opacity: 1; transform: translateY(0); }
-}
-
-/* ACARS Status Indicator */
-.acars-status-dot.listening {
-    background: var(--accent-cyan) !important;
-    animation: acars-pulse 1.5s ease-in-out infinite;
-}
-.acars-status-dot.receiving {
-    background: var(--accent-green) !important;
-}
-.acars-status-dot.error {
-    background: var(--accent-red) !important;
-}
-@keyframes acars-pulse {
-    0%, 100% { opacity: 1; box-shadow: 0 0 0 0 rgba(var(--accent-cyan-rgb), 0.7); }
-    50% { opacity: 0.6; box-shadow: 0 0 6px 3px rgba(var(--accent-cyan-rgb), 0.3); }
-}
-
-/* ACARS Standalone Message Feed */
-.acars-message-feed {
-    scrollbar-width: thin;
-    scrollbar-color: var(--border-color) transparent;
-}
-.acars-message-feed::-webkit-scrollbar {
-    width: 4px;
-}
-.acars-message-feed::-webkit-scrollbar-thumb {
-    background: var(--border-color);
-    border-radius: 2px;
-}
-.acars-feed-card {
-    transition: background 0.15s;
-}
-.acars-feed-card:hover {
-    background: rgba(var(--accent-cyan-rgb), 0.05);
-}
-
-/* Clickable ACARS sidebar messages (linked to tracked aircraft) */
-.acars-message-item[style*="cursor: pointer"]:hover {
-    background: rgba(var(--accent-cyan-rgb), 0.1);
-}

static/css/modes/vdl2.css

@@ -1,31 +0,0 @@
-/* VDL2 Mode Styles */
-
-/* VDL2 Status Indicator */
-.vdl2-status-dot.listening {
-    background: var(--accent-cyan) !important;
-    animation: vdl2-pulse 1.5s ease-in-out infinite;
-}
-.vdl2-status-dot.receiving {
-    background: var(--accent-green) !important;
-}
-.vdl2-status-dot.error {
-    background: var(--accent-red) !important;
-}
-@keyframes vdl2-pulse {
-    0%, 100% { opacity: 1; box-shadow: 0 0 0 0 rgba(var(--accent-cyan-rgb), 0.7); }
-    50% { opacity: 0.6; box-shadow: 0 0 6px 3px rgba(var(--accent-cyan-rgb), 0.3); }
-}
-
-/* VDL2 message animation */
-.vdl2-msg {
-    padding: 6px 8px;
-    border-bottom: 1px solid var(--border-color);
-    animation: vdl2FadeIn 0.3s ease;
-}
-.vdl2-msg:hover {
-    background: rgba(var(--accent-cyan-rgb), 0.05);
-}
-@keyframes vdl2FadeIn {
-    from { opacity: 0; transform: translateY(-3px); }
-    to { opacity: 1; transform: translateY(0); }
-}