Polish TUI and fix Codex tool call streaming

[smittyPNW]

Summary

• fix Codex/OpenAI tool-call streaming so final arguments from output item completion events are preserved
• polish the TUI shell with cleaner prompt, status, error, tool, and startup presentation
• add local launch and stop scripts for the patched Codex OAuth workflow

Testing

• npx bun run build
• npx bun test src/services/api/codexShim.test.ts
• CLAUDE_CODE_USE_OPENAI=1 OPENAI_MODEL=codexplan node dist/cli.mjs -p --bare --permission-mode bypassPermissions "Reply with exactly: facelift smoke ok"
• CLAUDE_CODE_USE_OPENAI=1 OPENAI_MODEL=codexplan node dist/cli.mjs -p --bare --permission-mode bypassPermissions --verbose --output-format stream-json "Use Bash to print the current directory name only."

[auriti]

Code Review

The core jsonBuffer approach is correct — accumulating streamed deltas and comparing against the canonical final payload in output_item.done is the right pattern. The startTextBlockIfNeeded / closeActiveTextBlock generator refactoring is clean. No conflicts with #237.

Several issues need addressing before merge:

---

Critical: flush logic ambiguity

The response.output_item.done handler compares finalArgs.length > toolBlock.jsonBuffer.length to decide whether to emit a remainder delta. This silently does nothing when:

• finalArgs.length === toolBlock.jsonBuffer.length (assumes buffer is exact prefix — OK in ideal case)
• finalArgs.length < toolBlock.jsonBuffer.length (malformed stream delivered more deltas than the final payload) — silently proceeds with corrupt buffered JSON

Suggested fix:
```ts
if (finalArgs && finalArgs !== toolBlock.jsonBuffer) {
const remainder = finalArgs.slice(toolBlock.jsonBuffer.length)
if (remainder.length > 0) {
yield { type: 'content_block_delta', index: toolBlock.index,
delta: { type: 'input_json_delta', partial_json: remainder } }
}
toolBlock.jsonBuffer = finalArgs
}
```

---

Important: toolBlocksByItemId.delete key mismatch

```ts
toolBlocksByItemId.delete(String(item.id))
```

If item.id is undefined in the done event but the block was keyed with the fallback toolUseId, String(undefined) === 'undefined' won't match the original key. The entry leaks and the cleanup loop emits a spurious content_block_stop. Fix: mirror the exact key used during insertion:

```ts
const key = String(item.id ?? toolUseId)
toolBlocksByItemId.delete(key)
```

---

Important: test doesn't cover the actual flush path

The new test verifies input_json_delta events appear, but doesn't simulate the specific scenario: partial JSON via function_call_arguments.delta followed by a longer item.arguments in output_item.done that requires flushing the remainder. Without this fixture, the regression path is untested.

---

Minor

• CondensedLogo tagline 'Codex-ready terminal for any LLM' narrows the product positioning — worth a team discussion
• ⎿ → │ removes the end-cap visual on message boundaries — subjective but affects every response

---

What works well

• jsonBuffer accumulation pattern is architecturally correct
• startTextBlockIfNeeded / closeActiveTextBlock refactoring is clean
• Full SSE sequence test is a solid regression baseline
• No conflicts with #237

Fix the flush logic and the key mismatch, and this is ready.

[Vasanthdev2004]

@smittyPNW can you check that issues ?