fix(server): honor explicit provider runtime env overrides

Restore runtime controls only from configured provider env, while preserving inherited and session filtering. Carry finalized provider environments through spawn boundaries so a second scrub cannot drop explicit settings.

Cover configured controls across ACP launches and OpenCode V2 reconnect/resume, including both environment-builder consumer paths. Keep parent-session and inherited control filtering checks, and identify Pi/OMP Node RPC fixture coverage accurately.

docs/plugins.md

@@ -493,7 +493,8 @@ export default function contribute(server: PluginServerContext) {
 
 Declare `command: ["agent", "serve"]` when your provider launches an executable. The daemon applies
 `agents.providers.<id>.command` and `env`, resolves the executable against the effective PATH, and
-removes parent-session and daemon-control environment variables. `connect({ launch })` receives
+removes parent-session variables and inherited/session daemon-control values; explicitly configured
+provider env survives. `connect({ launch })` receives
 `{ command, args, env }`: an executable path, effective arguments, and the complete sanitized
 environment. Spawn with those values; do not merge the plugin process's environment back in.
 The launch travels as data through the same provider protocol for built-in and subprocess plugins.