feat: AI job filter — score jobs 0-10 with Claude Haiku before applying

- lib/filter.mjs: batch scoring engine (10 jobs/call, Claude Haiku)
- job_filter.mjs: standalone CLI with --dry-run and --stats flags
- Threshold configurable globally + per-search in search_config.json (filter_min_score, default 5)
- Job profiles (gtm/ae) passed as context via settings.filter.job_profiles
- Filtered jobs get status='filtered' with filter_score + filter_reason
- Filter errors pass jobs through (never block applications)
- status.mjs: added 'AI filtered' line to report

config/search_config.example.json

@@ -1,10 +1,12 @@
 {
   "_note": "Configure your job searches here. Each search runs on both listed platforms.",
   "first_run_days": 90,
+  "filter_min_score": 5,
   "searches": [
     {
       "name": "Founding GTM",
       "track": "gtm",
+      "filter_min_score": 5,
       "keywords": [
         "founding account executive",
         "first sales hire",
@@ -23,6 +25,7 @@
     {
       "name": "Enterprise AE",
       "track": "ae",
+      "filter_min_score": 5,
       "keywords": [
         "enterprise account executive SaaS remote",
         "senior account executive technical SaaS remote",