protocol: report session permission profiles (#18282)

## Why

Clients that observe `SessionConfigured` need the same canonical
permission view that app-server thread responses provide. Reporting the
profile in protocol events lets clients keep their local state
synchronized without reinterpreting legacy sandbox fields.

## What changed

This adds `permission_profile` to `SessionConfigured` and propagates it
through core, exec JSON output, MCP server messages, and TUI
history/widget handling.

## Verification

- `cargo test -p codex-tui permissions -- --nocapture`
- `cargo test -p codex-core --test all permissions_messages --
--nocapture`















































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[//]: # (BEGIN SAPLING FOOTER)
Stack created with [Sapling](https://sapling-scm.com). Best reviewed
with [ReviewStack](https://reviewstack.dev/openai/codex/pull/18282).
* #18288
* #18287
* #18286
* #18285
* #18284
* #18283
* __->__ #18282

codex-rs/exec/tests/event_processor_with_json_output.rs

@@ -115,6 +115,7 @@ fn session_configured_produces_thread_started_event() {
         approval_policy: AskForApproval::Never,
         approvals_reviewer: codex_protocol::config_types::ApprovalsReviewer::User,
         sandbox_policy: SandboxPolicy::new_read_only_policy(),
+        permission_profile: None,
         cwd: test_path_buf("/tmp/project").abs(),
         reasoning_effort: None,
         history_log_id: 0,