## Summary
Adds global runtime flag to enable/disable MCP support. (off by
default).
```yaml
runtime_flags:
mcp: true
```
## Related issues
Fix:
https://linear.app/pomerium/issue/ENG-2367/place-mcp-support-behind-a-runtime-flag
## User Explanation
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## Checklist
- [x] reference any related issues
- [ ] updated unit tests
- [ ] add appropriate label (`enhancement`, `bug`, `breaking`,
`dependencies`, `ci`)
- [ ] ready for review
* update tracing config definitions
* new tracing system
* performance improvements
* only configure tracing in envoy if it is enabled in pomerium
* [tracing] refactor to use custom extension for trace id editing (#5420)
refactor to use custom extension for trace id editing
* set default tracing sample rate to 1.0
* fix proxy service http middleware
* improve some existing auth related traces
* test fixes
* bump envoyproxy/go-control-plane
* code cleanup
* test fixes
* Fix missing spans for well-known endpoints
* import extension apis from pomerium/envoy-custom
Add a distinction between TCP routes depending on whether the To URL(s)
have the scheme tcp://. For routes with a TCP upstream, configure Envoy
to terminate CONNECT requests and open a TCP tunnel to the upstream
service (this is the current behavior). For routes without a TCP
upstream, configure Envoy to proxy CONNECT requests to the upstream.
This new mode can allow an upstream proxy server to terminate a CONNECT
request and open its own TCP tunnel to the final destination server.
(Note that this will typically require setting the preserve_host_header
option as well.)
Note that this requires Envoy 1.30 or later.
