fix(aio): drop the OTLP telemetry token from process env after reading it

The sandbox delivers POSTHOG_AGENT_OTEL_LOGS_TOKEN via the container
environment, which agent-spawned tool subprocesses inherit - so any `env`
dump in a persisted transcript or PR body would leak the key (flagged by
review bots on PostHog/posthog#71100).

bin.ts is the only consumer: parse it into the server config, then delete
it from process.env so children never see it. Defense in depth, not a
boundary - same-UID processes can still read the container's initial env
via /proc; the key itself remains a write-only capture token scoped to a
dedicated telemetry project.

No test: a one-line env mutation at the CLI entry with no cheap seam;
exercising it would mean spawning the CLI end to end.

Generated-By: PostHog Code
Task-Id: 0c511836-2180-455a-9b58-45df2a0661ec

Author: tatoalo

packages/agent/src/server/bin.ts

@@ -170,6 +170,13 @@ program
 
     const env = envResult.data;
 
+    // The telemetry token is only ever consumed here (into the server config);
+    // drop it from the process environment so tool subprocesses spawned by the
+    // agent don't inherit it and `env` dumps in persisted transcripts or PR
+    // bodies can't leak it. Defense in depth, not a boundary: same-UID
+    // processes can still read the container's initial env via /proc.
+    delete process.env.POSTHOG_AGENT_OTEL_LOGS_TOKEN;
+
     const mode = options.mode === "background" ? "background" : "interactive";
     const createPr = parseBooleanOption(options.createPr, "--createPr");
     const autoPublish = parseBooleanOption(