feat(extension): harden LinkedIn Easy Apply and local API access

Background: for LinkedIn job URLs, wait for the tab to settle on a real linkedin.com document instead of trusting the first SPA complete event (waitForLinkedInTabSettled).

Content script: target Easy Apply inside #interop-outlet shadow DOM with light-DOM fallbacks; refactor modal flow, timeouts, screening defaults (YES_NO_DEFAULTS), logging, and success detection for 2025+ UI.

Manifest: grant http://127.0.0.1/* so the extension can reach a local backend.

Popup: add .btn-secondary styles for secondary actions.

Author: Mahi6384

extension/background/background.js

@@ -211,7 +211,12 @@ async function processOneJob(application, jobUrl, platform, log) {
   log.info(`Tab ${tab.id} opened`);
 
   try {
-    await waitForTabComplete(tab.id, TAB_LOAD_TIMEOUT_MS);
+    const isLinkedInJob = /linkedin\.com/i.test(jobUrl);
+    if (isLinkedInJob) {
+      await waitForLinkedInTabSettled(tab.id, TAB_LOAD_TIMEOUT_MS);
+    } else {
+      await waitForTabComplete(tab.id, TAB_LOAD_TIMEOUT_MS);
+    }
     log.step("tabLoad", "complete");
 
     await delay(2500);
@@ -591,6 +596,25 @@ function waitForTabComplete(tabId, timeoutMs) {
   });
 }
 
+/** LinkedIn SPA: first "complete" can be shell-only; wait for real linkedin.com URL. */
+async function waitForLinkedInTabSettled(tabId, timeoutMs) {
+  const deadline = Date.now() + timeoutMs;
+  while (Date.now() < deadline) {
+    try {
+      const t = await chrome.tabs.get(tabId);
+      const url = t.url || "";
+      if (
+        t.status === "complete" &&
+        /linkedin\.com/i.test(url) &&
+        !url.startsWith("chrome://")
+      ) {
+        return;
+      }
+    } catch (_) {}
+    await delay(120);
+  }
+}
+
 // ── Broadcast ────────────────────────────────────────────────────────────────
 
 function broadcast(message, current, total) {