Preserve routed Codex child settings across resume

AGENTS.md

@@ -164,6 +164,6 @@ Fields live in `~/.codex/ucode.config.toml` and `/etc/codex/managed_config.toml`
 | `model_catalog_json` | Create/replace | Create/replace | In `~/.codex/config.toml`; `ug`'s own catalog reference, for a static model list |
 | `otel.trace_exporter` | Ignore | Create/replace | In `~/.codex/config.toml` on Linux when the config enables tracing, for Codex desktop; another exporter and other telemetry settings left alone |
 | `mcp_servers` | Ignore | Merge | Managed file; add/update the config's MCP server entries, other entries left alone |
-| Smart Router and Smart Router Orchestrator hooks | Merge | Merge | Launch-only `PreToolUse`, plus `UserPromptSubmit` and compact `SessionStart` with `ENABLE_SMART_ROUTER_ORCHESTRATOR=1`; Codex combines them with its native hook sources and applies project trust; `features.hooks` is enabled for a smart-routed launch |
+| Smart Router and Smart Router Orchestrator hooks | Merge | Merge | Launch-only `PreToolUse` and `PostToolUse`, plus `UserPromptSubmit` and compact `SessionStart` with `ENABLE_SMART_ROUTER_ORCHESTRATOR=1`; Codex combines them with its native hook sources and applies project trust; `features.hooks` is enabled for a smart-routed launch |
 
 </details>

README.md

@@ -286,6 +286,21 @@ is enabled, ug warns and falls back to subagent routing because the first-prompt
 wrapper requires a Unix terminal.
 The generated shell hooks expect Git Bash; PowerShell-only setups are not covered.
 
+Smart-routed interactive Codex sessions preserve a routed child's model and reasoning
+effort through native `close_agent` / `resume_agent` and subsequent `send_input`, including
+routed descendants. Both routing modes use the Codex app-server; subagent-only routing
+keeps the parent's model. UG passes the working directory to the remote TUI so Codex
+can show its normal folder-trust prompt and resolve the initial sandbox from its current
+configuration. Explicit `--cd`/`-C` and permission options are preserved.
+Codex must trust the generated hooks. If settings cannot be
+restored, UG blocks the follow-up with a retry message.
+
+This protection is verified with Codex 0.159.3 and requires its native thread-settings APIs.
+It covers children created through UG's smart-routing launcher, including later resumes
+in another smart-routed launch against the same workspace. Direct Codex, `codex exec`,
+explicit-model launch bypasses, and standalone evaluation plugins do not acquire the guard.
+Native multi-agent v2 retains its own saved-settings restore path.
+
 ### Smart Router Orchestrator
 
 Use `SMART_ROUTER_CONFIG_VERSION` at launch to select a smart-routing configuration.