the anthropic proxy binds PORT + 1

ANTHROPIC_PROXY_PORT is gone. It was 5051 hardcoded in four files: proxy.ts,
which binds it, and three others that guessed the same constant to find it.

It is the only sidecar that binds a fixed port, and that part is a real
constraint rather than an oversight. Every other one binds `port: 0`, lets the
kernel choose and reports back over the registration socket — which works because
their consumer is the platform. The proxy's consumer is `claude`, spawned by a
different pm2 process that needs ANTHROPIC_BASE_URL at spawn time and has no
channel to ask what port the proxy landed on. Two processes with nothing between
them have to agree in advance.

So the number must be predictable, but it need not be 5051 — a value chosen
against nothing, in the registered range, free to collide with anything the owner
installs later. The symptom of that collision would have been chat failing while
the rest of the platform looked healthy.

PORT + 1 keeps the predictability and drops both the constant and the variable.
Nothing to set, no second number to keep in agreement with the first, and the
pair moves together when the install moves.

Also corrects .env.example, which said the proxy "holds the API credential, which
lives in the host env". It does not. The upstream credential is the OAuth token
claude writes to ~/.claude/.credentials.json, and the ANTHROPIC_API_KEY the agent
presents is the proxy's own generated secret.

Verified the derivation at PORT=9000 and PORT=10000; all four consumers now import
it; every edited file parses. Still not typechecked — empty node_modules, frozen
installs.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/servers/api/tasks/pipeline-executor.ts

@@ -10,6 +10,7 @@ import { resolveBaseCwd } from '../chat/websocket';
 import { sendClaudeCodeStreaming } from '../../channels/send-claude-code';
 import type { TurnMessage, MessageCost } from '../chat/types';
 import * as jobManager from './pipeline-job-manager';
+import { ANTHROPIC_PROXY_URL } from '../../officer-url.mjs';
 
 const DEFAULT_MODEL = 'claude-code';
 
@@ -96,9 +97,8 @@ type RunStepParams = {
 };
 
 async function refreshProxyToken(): Promise<void> {
-  const port = process.env.ANTHROPIC_PROXY_PORT ?? '5051';
   try {
-    await fetch(`http://127.0.0.1:${port}/refresh`, { method: 'POST' });
+    await fetch(`${ANTHROPIC_PROXY_URL}/refresh`, { method: 'POST' });
   } catch {
     // Best effort — proxy may not be running (e.g. using API key directly)
   }