b94bfba025
- Client-generated HTTP/MCP/authorization headers win over configured
headers case-insensitively (Agent Plugins §7.2.1) via the new
header-policy fetch wrapper used by the HTTP and legacy SSE transports.
- headerPolicy: "origin-locked" pins configured headers to the configured
URL's origin: never forwarded across cross-origin redirects, and
method-changing redirects of JSON-RPC POSTs are refused.
- envPolicy: "literal" exempts stdio env values (and origin-locked
headers) from config-value resolution: no ambient env-name lookup, no
__omp_shell("command execution, empty values preserved.")