chore: remove obsolete APIs (register, probe, n8n, videos, people)

- Remove /api/v1/register (replaced by /api/v1/files/register)
- Remove /api/v1/probe (replaced by /api/v1/files/:uuid)
- Remove /api/v1/n8n/... (n8n workflow only)
- Remove /api/v1/unregister (high risk)
- Remove /api/v1/videos list (replaced by /api/v1/files)
- Remove /api/v1/people (merged into /api/v1/identities)
- Clean up dead code and unused structs

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "momentry_core"
-version = "0.1.0"
+version = "1.0.0"
 edition = "2021"
 authors = ["Momentry Team"]
 description = "Digital asset management system with video analysis and RAG"