feat: redesign collection UI + add StopHostAfterCollect + TCP ping pre-probe

- Single "Подключиться" button flow: probe first, then show collect options
- Power management checkboxes: power on before / stop after collect
- Modal confirmation when enabling shutdown on already-powered-on host
- StopHostAfterCollect flag: host shuts down only when explicitly requested
- TCP ping (10 attempts, min 3 successes) before Redfish probe
- Debug payloads checkbox (Oem/Ami/Inventory/Crc, off by default)
- Remove platform_config BIOS settings collection (unreliable on AMI)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/static/css/style.css

@@ -210,7 +210,6 @@ main {
     pointer-events: none;
 }
 
-#api-check-btn,
 #api-connect-btn,
 #api-power-on-collect-btn,
 #api-collect-off-btn,
@@ -229,7 +228,6 @@ main {
     transition: background-color 0.2s ease, opacity 0.2s ease;
 }
 
-#api-check-btn:hover,
 #api-connect-btn:hover,
 #api-power-on-collect-btn:hover,
 #api-collect-off-btn:hover,
@@ -242,7 +240,6 @@ main {
 
 #convert-run-btn:disabled,
 #convert-folder-btn:disabled,
-#api-check-btn:disabled,
 #api-connect-btn:disabled,
 #api-power-on-collect-btn:disabled,
 #api-collect-off-btn:disabled,
@@ -252,6 +249,127 @@ main {
     cursor: not-allowed;
 }
 
+#api-collect-btn {
+    background: #1f8f4c;
+    color: #fff;
+    border: none;
+    border-radius: 6px;
+    padding: 0.6rem 1.25rem;
+    font-size: 0.95rem;
+    font-weight: 600;
+    cursor: pointer;
+    transition: background-color 0.2s ease, opacity 0.2s ease;
+}
+
+#api-collect-btn:hover {
+    background: #176e3a;
+}
+
+#api-collect-btn:disabled {
+    opacity: 0.6;
+    cursor: not-allowed;
+}
+
+.api-probe-options {
+    margin-top: 0.9rem;
+    display: flex;
+    flex-direction: column;
+    gap: 0.45rem;
+}
+
+.api-form-checkbox {
+    display: flex;
+    align-items: center;
+    gap: 0.45rem;
+    font-size: 0.9rem;
+    cursor: pointer;
+    user-select: none;
+}
+
+.api-form-checkbox input[type="checkbox"] {
+    width: 1rem;
+    height: 1rem;
+    cursor: pointer;
+}
+
+.api-form-checkbox input[type="checkbox"]:disabled {
+    cursor: not-allowed;
+    opacity: 0.6;
+}
+
+.api-form-checkbox span {
+    color: #444;
+}
+
+.api-form-checkbox-sub {
+    padding-left: 0.25rem;
+    opacity: 0.8;
+}
+
+.api-probe-options-separator {
+    margin: 0.5rem 0;
+    border-top: 1px solid #e2e8f0;
+}
+
+.api-confirm-modal-backdrop {
+    position: fixed;
+    inset: 0;
+    background: rgba(0, 0, 0, 0.45);
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    z-index: 1000;
+}
+
+.api-confirm-modal {
+    background: #fff;
+    border-radius: 10px;
+    padding: 1.5rem 1.75rem;
+    max-width: 380px;
+    width: 90%;
+    box-shadow: 0 8px 32px rgba(0,0,0,0.18);
+}
+
+.api-confirm-modal p {
+    margin-bottom: 1.1rem;
+    font-size: 0.95rem;
+    color: #333;
+    line-height: 1.5;
+}
+
+.api-confirm-modal-actions {
+    display: flex;
+    gap: 0.6rem;
+    justify-content: flex-end;
+}
+
+.api-confirm-modal-actions button {
+    border: none;
+    border-radius: 6px;
+    padding: 0.5rem 1rem;
+    font-size: 0.9rem;
+    font-weight: 600;
+    cursor: pointer;
+}
+
+.api-confirm-modal-actions .btn-cancel {
+    background: #e2e8f0;
+    color: #333;
+}
+
+.api-confirm-modal-actions .btn-cancel:hover {
+    background: #cbd5e1;
+}
+
+.api-confirm-modal-actions .btn-confirm {
+    background: #dc3545;
+    color: #fff;
+}
+
+.api-confirm-modal-actions .btn-confirm:hover {
+    background: #b02a37;
+}
+
 .api-connect-status {
     margin-top: 0.75rem;
     font-size: 0.85rem;