refactor: extract magic numbers to constants, fix audit issues

- Centralize all magic numbers/strings in lib/constants.mjs
- Fix double-replaced import names in filter.mjs
- Consolidate duplicate fs imports in job_applier/job_searcher
- Remove empty JSDoc block in job_searcher
- Update keywords.mjs model from claude-3-haiku to claude-haiku-4-5
- Extract Anthropic API URLs to constants
- Convert :has-text() selectors to page.locator() API
- Fix SIGTERM handler conflict — move partial-run notification into lock.onShutdown
- Remove unused exports (LOCAL_USER_AGENT, DEFAULT_REVIEW_WINDOW_MINUTES)
- Fix variable shadowing (b -> v) in job_filter reduce callback
- Replace SKILL.md PM2 references with system cron

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

lib/session.mjs

@@ -3,10 +3,12 @@
  * Call refreshSession() before creating a browser to ensure the profile is fresh
  */
 import { createRequire } from 'module';
+import {
+  KERNEL_SDK_PATH, SESSION_REFRESH_POLL_TIMEOUT, SESSION_REFRESH_POLL_WAIT,
+  SESSION_LOGIN_VERIFY_WAIT
+} from './constants.mjs';
 const require = createRequire(import.meta.url);
 
-const KERNEL_SDK_PATH = '/home/ubuntu/.openclaw/workspace/node_modules/@onkernel/sdk/index.js';
-
 export async function refreshSession(platform, apiKey, connectionIds = {}) {
   const connectionId = connectionIds[platform];
   if (!connectionId) throw new Error(`No Kernel connection ID configured for platform: ${platform} — add it to settings.json under kernel.connection_ids`);
@@ -28,8 +30,8 @@ export async function refreshSession(platform, apiKey, connectionIds = {}) {
   console.log(`  ⏳ ${platform} session pending (status: ${loginResp.status}), polling...`);
   const start = Date.now();
   let pollCount = 0;
-  while (Date.now() - start < 30000) {
-    await new Promise(r => setTimeout(r, 2000));
+  while (Date.now() - start < SESSION_REFRESH_POLL_TIMEOUT) {
+    await new Promise(r => setTimeout(r, SESSION_REFRESH_POLL_WAIT));
     pollCount++;
     const conn = await kernel.auth.connections.retrieve(connectionId);
     if (conn.status === 'SUCCESS') {
@@ -58,7 +60,7 @@ export async function ensureLoggedIn(page, verifyFn, platform, apiKey, connectio
       console.warn(`  ⚠️  ${platform} not logged in (attempt ${attempt}), refreshing session...`);
       await refreshSession(platform, apiKey, connectionIds);
       await page.reload({ waitUntil: 'domcontentloaded' });
-      await page.waitForTimeout(3000);
+      await page.waitForTimeout(SESSION_LOGIN_VERIFY_WAIT);
     }
   }
   return false;