cmd: set codex env vars on launch and handle zstd request bodies (#14122)

The Codex runner was not setting OPENAI_BASE_URL or OPENAI_API_KEY, this prevents Codex from sending requests to api.openai.com instead of the local Ollama server. This mirrors the approach used by the Claude runner.

Codex v0.98.0 sends zstd-compressed request bodies to the /v1/responses endpoint. Add decompression support in ResponsesMiddleware with an 8MB max decompressed size limit to prevent resource exhaustion.

cmd/config/codex.go

@@ -6,6 +6,7 @@ import (
 	"os/exec"
 	"strings"
 
+	"github.com/ollama/ollama/envconfig"
 	"golang.org/x/mod/semver"
 )
 
@@ -32,6 +33,10 @@ func (c *Codex) Run(model string, args []string) error {
 	cmd.Stdin = os.Stdin
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
+	cmd.Env = append(os.Environ(),
+		"OPENAI_BASE_URL="+envconfig.Host().String()+"/v1/",
+		"OPENAI_API_KEY=ollama",
+	)
 	return cmd.Run()
 }