Fix CF-271: Add fallback text search to archive_search

When LiteLLM embedding service is unavailable, archive_search now gracefully falls back to PostgreSQL text search (ILIKE) instead of returning an error. Also adds dotenv support for proper credential loading.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

package-lock.json

@@ -9,6 +9,7 @@
       "version": "1.0.0",
       "dependencies": {
         "@modelcontextprotocol/sdk": "^1.0.4",
+        "dotenv": "^17.2.3",
         "pg": "^8.11.3"
       },
       "devDependencies": {
@@ -734,6 +735,18 @@
         "node": ">= 0.8"
       }
     },
+    "node_modules/dotenv": {
+      "version": "17.2.3",
+      "resolved": "https://registry.npmjs.org/dotenv/-/dotenv-17.2.3.tgz",
+      "integrity": "sha512-JVUnt+DUIzu87TABbhPmNfVdBDt18BLOWjMUFJMSi/Qqg7NTYtabbvSNJGOJ7afbRuv9D/lngizHtP7QyLQ+9w==",
+      "license": "BSD-2-Clause",
+      "engines": {
+        "node": ">=12"
+      },
+      "funding": {
+        "url": "https://dotenvx.com"
+      }
+    },
     "node_modules/dunder-proto": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/dunder-proto/-/dunder-proto-1.0.1.tgz",