feat: add DuckDuckGo Email Protection autofill settings

- Implemented a new content script for DuckDuckGo Email autofill functionality.
- Enhanced email polling scripts (mail-163.js, qq-mail.js, signup-page.js, vps-panel.js) to handle user flow interruptions.
- Updated utility functions to manage flow stopping and error handling.
- Introduced a stop button in the side panel for user control over ongoing processes.
- Improved UI elements and styles for better user experience, including new button states and messages.
- Adjusted the side panel to fetch DuckDuckGo email automatically and display it in the input field.

sidepanel/sidepanel.css

@@ -173,6 +173,12 @@ header {
 }
 .btn-success:hover { opacity: 0.9; box-shadow: 0 2px 8px var(--green-soft); }
 
+.btn-danger {
+  background: var(--red);
+  color: #fff;
+}
+.btn-danger:hover { opacity: 0.9; box-shadow: 0 2px 8px var(--red-soft); }
+
 .run-group {
   display: flex;
   align-items: center;
@@ -194,7 +200,7 @@ header {
 }
 .run-count-input:focus { border-color: var(--blue); }
 .run-count-input::-webkit-inner-spin-button { opacity: 0.5; }
-.btn-success:disabled, .btn-primary:disabled { background: var(--bg-elevated); color: var(--text-muted); cursor: not-allowed; box-shadow: none; }
+.btn-success:disabled, .btn-primary:disabled, .btn-danger:disabled { background: var(--bg-elevated); color: var(--text-muted); cursor: not-allowed; box-shadow: none; }
 .run-count-input:disabled { opacity: 0.5; cursor: not-allowed; }
 
 .btn-ghost {
@@ -238,6 +244,14 @@ header {
   gap: 8px;
 }
 
+.data-inline {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  flex: 1;
+  min-width: 0;
+}
+
 .data-label {
   width: 56px;
   font-size: 11px;
@@ -283,6 +297,10 @@ header {
 .data-input::placeholder { color: var(--text-muted); }
 .data-input:focus { border-color: var(--blue); box-shadow: 0 0 0 3px var(--blue-soft); }
 
+#btn-fetch-email {
+  padding-inline: 10px;
+}
+
 .data-select {
   flex: 1;
   padding: 7px 10px;
@@ -337,6 +355,9 @@ header {
 .status-bar.failed .status-dot { background: var(--red); }
 .status-bar.failed { color: var(--red); }
 
+.status-bar.stopped .status-dot { background: var(--cyan); }
+.status-bar.stopped { color: var(--cyan); }
+
 @keyframes pulse {
   0%, 100% { opacity: 1; transform: scale(1); }
   50% { opacity: 0.4; transform: scale(0.85); }
@@ -433,6 +454,9 @@ header {
 .step-row.failed .step-indicator { border-color: var(--red); background: var(--red-soft); }
 .step-row.failed .step-num { color: var(--red); }
 
+.step-row.stopped .step-indicator { border-color: var(--cyan); background: rgba(8, 145, 178, 0.08); }
+.step-row.stopped .step-num { color: var(--cyan); }
+
 /* Step Button */
 .step-btn {
   flex: 1;
@@ -455,6 +479,7 @@ header {
 .step-row.running .step-btn { border-color: var(--orange); color: var(--orange); }
 .step-row.completed .step-btn { border-color: var(--border-subtle); color: var(--text-secondary); opacity: 0.7; }
 .step-row.failed .step-btn { border-color: var(--red); color: var(--red); }
+.step-row.stopped .step-btn { border-color: var(--cyan); color: var(--cyan); }
 
 .step-status {
   width: 20px;
@@ -465,6 +490,7 @@ header {
 }
 .step-row.completed .step-status { color: var(--green); }
 .step-row.failed .step-status { color: var(--red); }
+.step-row.stopped .step-status { color: var(--cyan); }
 
 /* ============================================================
    Log / Console Section