/learn-taste learns nothing from Codex sessions: extractor only reads legacy event_msg/user_message format

What happens

/learn-taste (and cmd learn-taste) finds my Codex sessions but learns nothing from them. Taste onboarding ends with "TASTE Skipped", and ~/.commandcode/taste/ stays empty. Projects whose history is Codex-only get zero taste signal.

Environment

• Command Code v1.53.1 (command-code npm global, cmdc), Windows 11, PowerShell
• Codex CLI 0.154.0, sessions at ~/.codex/sessions/YYYY/MM/DD/rollout-*.jsonl

Root cause: stale Codex prompt extractor

The session finder works (3-level YYYY/MM/DD walk + rollout-*.jsonl + session_meta.payload.cwd project match). But extractCodexPrompts only accepts lines shaped as:

{ "type": "event_msg", "payload": { "type": "user_message", "message": "..." } }

That shape no longer exists in Codex rollouts. Verified on this machine:

• Newest rollout (Sept 2026): 165 lines, 62 event_msg, 0 with payload.type: "user_message". event_msg payloads are only item_completed, token_count, task_started, task_complete.
• Search for "user_message" across all September rollouts: 0 hits. A May 2026 archived rollout: also 0.
• Conversation turns now live in response_item entries:

{ "type": "response_item", "payload": { "type": "message", "role": "user", "content": [{ "type": "input_text", "text": "..." }] } }

(role is user / assistant / developer; user text parts use type: "input_text", assistant uses output_text.)

So extraction always yields [] → nothing to learn.

Suggested fix

In extractCodexPrompts, also handle type: "response_item" with payload.type: "message" and payload.role: "user", joining payload.content[].text for input_text parts. (Note: some role: "user" items are injected context like <environment_context> / skills text — you may want to skip those or let the taste model filter them.)

Secondary issue: case-sensitive cwd match on Windows

The project filter compares session_meta.payload.cwd === projectPath exactly. On Windows, recorded cwd case varies between sessions (e:\development\... vs E:\development\...), so matches are silently missed. Suggest case-insensitive comparison + separator normalization on win32.

Repro

1. Have Codex-only history in a project (any recent Codex CLI).
2. Run cmdc, then /learn-taste (or cmdc learn-taste) from that project dir.
3. Observe: sessions are scanned, but no taste is learned.

从 extractCodexPrompts 开始，跟踪 /learn-taste 和 cmd learn-taste 使用的会话处理逻辑。处理 response_item 条目中的用户消息，然后检查 session_meta.payload.cwd 项目过滤器在 Windows 上的大小写和分隔符差异。完成的标志是，最近的仅 Codex 会话能够生成 taste 输入，并且匹配的项目路径不会在 Windows 上被静默跳过。