Reduce TUI legacy core dependencies

[etraut-openai]

Why

The TUI still reached through app-server-client::legacy_core for thread-name normalization and project-instruction filename details. In particular, checking the TUI's local filesystem for /init is incorrect for remote app-server sessions, where the server owns the working directory and instruction discovery.

What changed

• use the instruction source paths supplied by the app server to decide whether /init should avoid overwriting project instructions
• keep the small thread-name normalization helper local to the TUI
• remove the now-unused instruction filename constants, utility module, and other unused legacy_core re-exports
• make status helper tests independent of concrete instruction filenames

Verification

• just test -p codex-app-server-client
• just test -p codex-tui slash_init_skips_when_project_instructions_are_loaded
• just test -p codex-tui ran 2,799 tests; 2,797 passed and two unrelated guardian feature-flag tests failed reproducibly in untouched code

Manual test

Started an app server over WebSocket with a remote workspace containing AGENTS.md, then connected the TUI using --remote. After confirming thread/start returned the file in instructionSources, deleted AGENTS.md and ran /init in the existing session.

The TUI still reported that project instructions already existed and skipped /init. The trace contained no turn/start request, confirming the decision came from app-server session state rather than a new client-local filesystem check.

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

💡 Codex Review

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[chatgpt-codex-connector]

💡 Codex Review

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Reviewed commit: 08811b5e35

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• Open a pull request for review
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Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Add integration coverage for /init behavior

Under AGENTS.md Test authoring guidance, agent-logic changes need integration coverage. This line changes /init model behavior by requiring an existing-AGENTS.md check before writing, but the diff only verifies that the TUI queues the prompt, so regressions in the actual agent behavior can still pass. Please add an integration test for existing-AGENTS.md handling.

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