feat(sdk): AuthConfigs, JSON Schema, examples, and release checksum CI

Add craftlabs-auth-config.schema.json, Java AuthConfigs model with tests,
example configs aligned to BP-10, C/Java/auth-config documentation,
native header notes, RELEASING guide, and workflow to verify SDK
artifact checksums on release tags.

Made-with: Cursor

examples/config/floating.bitanswer.json

@@ -0,0 +1,17 @@
+{
+  "schemaVersion": 1,
+  "provider": "bitanswer",
+  "scenario": "floating",
+  "bitanswer": {
+    "url": "https://cloud.bitanswer.example/e3",
+    "loginMode": "REMOTE"
+  },
+  "features": {
+    "face": { "bitanswerFeatureId": 301 }
+  },
+  "floating": {
+    "projectId": "migrant-flow-prj-2026-001",
+    "projectName": "某市流动人口人像核验",
+    "contractRef": "PO-2026-8848"
+  }
+}