feat(codex): create and customize Codex config from /settings

Adds the Codex config panel (skills/agents/rules/memory/config editing,
mcp/plugins/marketplaces add-remove via the codex CLI) as the last piece
of parity with the Claude Code settings tab, plus the codex_config_changed
WebSocket type the client was missing, and docs for the new
/api/codex-config surface.

client/src/lib/types.ts

@@ -545,6 +545,7 @@
  *  - `run_stream` / `run_status` / `run_input_ack` ... {@link RunStreamPayload} /
  *    {@link RunStatusPayload} / {@link RunInputAckPayload}
  *  - `cc_config_changed` ............................ {@link CcConfigChangedPayload}
+ *  - `codex_config_changed` ......................... {@link CodexConfigChangedPayload}
  *  - `alert_triggered` / `alert_updated` ............ {@link AlertEvent}
  *  - `workflow_upserted` ............................ {@link WorkflowRun}
  *
@@ -1331,6 +1332,24 @@ export interface CcConfigChangedPayload {
   paths?: string[];
 }
 
+// ───── Codex config change notifications ─────
+
+/** Payload for the `codex_config_changed` WebSocket message: broadcast
+ *  whenever a Codex CLI config artifact (skill, agent, rule, memory, config,
+ *  MCP server, plugin, marketplace) is written or removed through the
+ *  dashboard's codex-config editor, so other open tabs can refresh their
+ *  view. Codex has no filesystem watcher counterpart to `cc-watcher.js`, so
+ *  unlike {@link CcConfigChangedPayload} this is always dashboard-sourced. */
+export interface CodexConfigChangedPayload {
+  source: "dashboard";
+  action?: "write" | "delete";
+  /** "user" or "project" - Codex has no "project-local" scope. */
+  scope?: "user" | "project";
+  /** Artifact kind, e.g. "skills", "agents", "rules", "memory", "config". */
+  type?: string;
+  name?: string | null;
+}
+
 // ───── Alerting ─────
 // User-defined rules that watch the ingest stream (or a periodic sweep) and fire
 // {@link AlertEvent}s. {@link AlertRuleConfig} is a tagged bag of settings whose
@@ -1624,6 +1643,7 @@ export interface WSMessage {
    *  new_event → DashboardEvent; import.progress → ImportProgressMessage;
    *  update_status → UpdateStatusPayload; run_stream/run_status/run_input_ack
    *  → their matching Run*Payload; cc_config_changed → CcConfigChangedPayload;
+   *  codex_config_changed → CodexConfigChangedPayload;
    *  alert_triggered/alert_updated → AlertEvent; workflow_upserted → WorkflowRun;
    *  remote_source.status → RemoteSourceStatusPayload;
    *  remote_data.updated → RemoteDataUpdatedPayload;
@@ -1640,6 +1660,7 @@ export interface WSMessage {
     | "run_status"
     | "run_input_ack"
     | "cc_config_changed"
+    | "codex_config_changed"
     | "alert_triggered"
     | "alert_updated"
     | "workflow_upserted"
@@ -1661,6 +1682,7 @@ export interface WSMessage {
     | UpdateStatusPayload
     | RunStatusPayload
     | CcConfigChangedPayload
+    | CodexConfigChangedPayload
     | AlertEvent
     | WorkflowRun
     | RemoteSourceStatusPayload