fix: deliver server-initiated requests (elicitation, sampling, roots)…

… via POST response SSE

Per the MCP spec, the server SHOULD deliver JSON-RPC requests that relate
to a specific client request on the POST response stream for that request.

Previously, server-initiated requests (elicitation/create, sampling/createMessage,
roots/list) were only delivered via the GET/SSE listener. Clients that don't
open a GET listener (e.g., bridge-based clients like MCPJam Inspector) would
never receive these requests, causing elicitation to time out.

This commit adds elicitationRequestChan, samplingRequestChan, and
rootsRequestChan to the POST handler's goroutine alongside the existing
notificationChannel handling. The SSE write logic is extracted into a
shared helper to avoid duplication.

fmt

fix: Add missing session cleanup to the StreamableHTTPServer DELETE h…

…andler (mark3labs#667)

* fix: Add missing session cleanup to the StreamableHTTPServer DELETE handler

* Fix merge typo

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Co-authored-by: Connor Zanin <176337368+connor-strata@users.noreply.github.com>

fix: handle either $defs or definitions field when unmarshaling ToolA…

…rgumentsSchema (mark3labs#645)

Older versions of the JSON Schema spec use the "definitions" field,
while newer versions use "$defs". This can be seen in the Honeycomb
MCP, which uses "definitions".

This commit adds support for both fields, and prefers "$defs" over
"definitions" if both are present.

fmt + fix linting errors

fix: custom header (mark3labs#632)

update CI/CD