JWT Bearer auth (HS256/HS512) and release prep 1.3.25

[LunatikDG]

Summary

• Add JWT Bearer (JwtBearer): HS256/HS512 via platform hashing + HMAC (RFC 2104); fields algorithm / secret / claims / ttlSeconds (iat/exp when TTL > 0).
• Move auth schema and crypto into the data processor object module; thin adapters on main and collection forms.
• Postman jwt import/export for HS*; bump version to 1.3.25 and move CHANGELOG entries under that release.

Partial for #13: only HMAC HS256/HS512 in this PR (no RS*/HS384 yet). Issue stays open for follow-up.

Refs #13

Test plan

• JwtBearer HS256/HS512 → httpbin.org/bearer shows Authorization: Bearer eyJ…
• jwt.io verifies signature with the same secret; iat/exp sane when TTL > 0
• TTL = 0 does not add iat/exp
• Basic auth / Bearer Token / API Key still work after auth refactor
• Client and Server send contexts