fix(#2406): stop Codex config.toml from double-registering agent roles (#2432)

* fix(#2406): stop Codex config.toml from double-registering agent roles

generateCodexConfigBlock emitted an [agents.<name>] role table per agent
pointing config_file back at the standalone agents/<name>.toml Codex
already auto-discovers, so every install declared each role twice in
one config layer and Codex logged a duplicate-role warning per agent.
Remove the redundant role-table loop; the standalone per-agent TOML is
now the sole canonical registration source. The existing marker-truncate
and leaked-section stripping in mergeCodexConfig already clean up legacy
[agents.gsd-*] tables from prior installs, so updates converge to zero
duplicates without any new migration path.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* chore(#2406): regenerate fixtures + lint gate-prep

* fix(#2406): repair failing tests after gate verification

* docs(#2406): add changeset for Codex duplicate agent-role fix

Adds the missing .changeset/*.md fragment for the Codex config.toml
double-registration fix, closing the PR-gate finding from review.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* chore(#2406): backfill changeset pr (#2432)

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

docs/reference/host-integration-capability-matrix.md

@@ -105,7 +105,7 @@ Sources consulted:
 
 - **Skill root** — skills install to the canonical `$HOME/.agents/skills` (Codex core-skills `loader.rs` user-scope root), not the deprecated `$CODEX_HOME/skills` fallback. Declared via the skills-kind `home: ".agents"` override; pre-move installs are migrated (stale `~/.codex/skills/gsd-*` cleaned on both install and uninstall).
 - **Hook events** — GSD registers all documented `hooks.json` lifecycle events beyond `SessionStart`: `SubagentStart`, `Stop`, `PostToolUse` (#772), plus the six added in #2088 — `PreToolUse`, `PermissionRequest`, `PreCompact`, `PostCompact`, `SubagentStop`, `UserPromptSubmit` — all routed through `gsd-context-monitor.js`. (The descriptor `extendedHookEvents` field reflects the schema-valid cross-runtime subset `SubagentStop`/`Stop`/`PreCompact`; Codex's full event set is codex-hooks-json-native, registered directly in `hooks.json`.)
-- **Dispatch tuning** — `[agents] max_depth = 1` is written explicitly into the managed `config.toml` block, pinning the `dispatch.maxDepth: 1` axis instead of relying on codex-cli's implicit default. Because `maxDepth === 1`, `degradationFor` flattens GSD-hosted wave dispatch to single-level even though `dispatch.nested`/`background`/`backgroundDispatch` are all `true`. The block is a bare `[agents]` AgentsToml scalar table (coexisting with the flattened `[agents.gsd-*]` role sub-tables); `validateCodexConfigSchema` permits a known-scalar-only `[agents]` while still rejecting `[[agents]]` and unknown-key forms.
+- **Dispatch tuning** — `[agents] max_depth = 1` is written explicitly into the managed `config.toml` block, pinning the `dispatch.maxDepth: 1` axis instead of relying on codex-cli's implicit default. Because `maxDepth === 1`, `degradationFor` flattens GSD-hosted wave dispatch to single-level even though `dispatch.nested`/`background`/`backgroundDispatch` are all `true`. The block is a bare `[agents]` AgentsToml scalar table; it does **not** carry per-role `[agents.gsd-*]` sub-tables — those pointed `config_file` back at the standalone `agents/gsd-*.toml` files Codex already auto-discovers, so emitting them was a duplicate role registration (Codex logged "Ignoring malformed agent role definition: duplicate agent role name" once per agent) removed in #2406. `validateCodexConfigSchema` permits a known-scalar-only `[agents]` while still rejecting `[[agents]]` and unknown-key forms.
 
 Sources consulted:
 - https://github.com/openai/codex (repo via gh CLI)