fix: improve Codex workspace run and rerun parity

[VasuBansal7576]

Description

Improves the workspace/UI parity needed for Codex-built agents: run-button gating, structured run questions, and rerun reuse of previously supplied inputs.

Stacked on top of PR2: #5

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactoring (no functional changes)

Related Issues

Related to aden-hive#6741
Related to aden-hive#6817

Changes Made

• add shared frontend helpers for structured run-input key discovery and run-button gating
• only show Run when the worker is actually in a runnable phase
• prompt for missing structured run inputs and reuse them for reruns instead of dropping them
• preserve the current upstream workspace UI while applying the Codex parity behavior

Testing

Ran the following tests locally:

• cd core/frontend && npm run test -- --run src/lib/run-inputs.test.ts
• cd core/frontend && npm run build
• Manual testing performed on the full stacked branch in the UI

Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

Screenshots (if applicable)

N/A

[github-actions]

PR Closed - Requirements Not Met

This PR has been automatically closed because it doesn't meet the requirements.

PR Author: @VasuBansal7576
Found issues:
Problem: The PR author must be assigned to the linked issue.

To fix:

1. Assign yourself (@VasuBansal7576) to one of the linked issues
2. Re-open this PR

Exception: To bypass this requirement, you can:

• Add the micro-fix label or include micro-fix in your PR title for trivial fixes
• Add the documentation label or include doc/docs in your PR title for documentation changes

Micro-fix requirements (must meet ALL):

Qualifies	Disqualifies
< 20 lines changed	Any functional bug fix
Typos & Documentation & Linting	Refactoring for "clean code"
No logic/API/DB changes	New features (even tiny ones)

Why is this required? See aden-hive#472 for details.

[VasuBansal7576]

Closing this in favor of the single consolidated PR: aden-hive#6831