feat: hot-reloaded runtime config (src/lib/runtime-config.ts), greeting on GET /, GET /admin/runtime-config

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

package-lock.json

@@ -15,6 +15,7 @@
         "pino": "^9.5.0",
         "pino-http": "^10.3.0",
         "unleash-client": "^6.12.2",
+        "yaml": "^2.9.1",
         "zod": "^3.24.0"
       },
       "devDependencies": {
@@ -6290,6 +6291,21 @@
       "integrity": "sha512-3wdGidZyq5PB084XLES5TpOSRA3wjXAlIWMhum2kRcv/41Sn2emQ0dycQW4uZXLejwKvg6EsvbdlVL+FYEct7A==",
       "license": "ISC"
     },
+    "node_modules/yaml": {
+      "version": "2.9.1",
+      "resolved": "https://registry.npmjs.org/yaml/-/yaml-2.9.1.tgz",
+      "integrity": "sha512-3NxN8+78OdzbT7C/WjGsyfPAtJaN3FNDsWxv7Y7mcDsT/oOmgW8BpyQQFFBnvZE3j9Y2Sdz1ULFLezL7Eb2yFw==",
+      "license": "ISC",
+      "bin": {
+        "yaml": "bin.mjs"
+      },
+      "engines": {
+        "node": ">= 14.6"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/eemeli"
+      }
+    },
     "node_modules/yargs": {
       "version": "17.7.3",
       "resolved": "https://registry.npmjs.org/yargs/-/yargs-17.7.3.tgz",