fix(turns): restore initial Agent selection for unlocked positions (#322)

[Bindy-lbb]

Tracking record

Closes #322

Summary

In PR #300 (#297, commit 8985c2f), TurnPanel.tsx refactored the conversation header to display a fixed Agent identity badge (<EngineBadge>), dropping engineLocked and onSelectEngine from parameter destructuring under the assumption that Agent selection only occurs during employee creation via HireDrawer.

This broke the contract established in PR #289 (feat(runtime): lock initial Agent selection (#289), commit 2feefda) for externally imported digital employees. When an employee is imported from an external kit or showcase without pre-locked bindings (agentLocked: false), they never pass through HireDrawer. Consequently, operators had no UI affordance in the conversation header to select an initial runtime.

This PR restores the conditional rendering of <EngineSelect> when engineLocked is false, while preserving the noninteractive <EngineBadge> display for locked positions (engineLocked: true).

Acceptance criteria

Acceptance criterion	Status	Implementation / evidence
AC-001: When an imported employee has not locked an Agent (engineLocked: false), the conversation header renders an interactive <EngineSelect> component permitting initial runtime selection.	PASS	TurnPanel.tsx:248-260, covered by TurnPanel.test.tsx and App.test.tsx
AC-002: Selecting an Agent via <EngineSelect> dispatches onSelectEngine, which persists the choice, locks the position (engineLocked: true), and transitions the UI to the static <EngineBadge> display.	PASS	TurnPanel.tsx:258, App.tsx:1027-1049 (changeEmployeeAgentEngine)
AC-003: When an employee already has a locked Agent (engineLocked: true), the header renders <EngineBadge> with no interactive dropdown.	PASS	TurnPanel.tsx:250-252, TurnPanel.test.tsx:121-155
AC-004: All existing renderer test suites pass without regressions, and typechecks succeed.	PASS	TurnPanel.test.tsx (27/27), conversation-interaction.test.tsx (18/18), App.test.tsx (81/81), npm run typecheck:renderer (0 errors), npm run build:renderer

Validation ledger

Command or check	Expected	Actual	Evidence
npm run typecheck:renderer	0 errors	0 errors	tsc --noEmit -p apps/desktop passed
node scripts/run-renderer-tests.mjs apps/desktop/renderer/test/TurnPanel.test.tsx	27/27 pass	27/27 pass	Tests include #322 renders EngineSelect for an unlocked position and EngineBadge when locked
node scripts/run-renderer-tests.mjs apps/desktop/renderer/test/conversation-interaction.test.tsx	18/18 pass	18/18 pass	Tests include shows an interactive EngineSelect when engineLocked=false
node scripts/run-renderer-tests.mjs apps/desktop/renderer/test/App.test.tsx -t "Agent"	All pass	8/8 pass (73 skipped)	Tests include #322 opens an unlocked employee direct conversation with an interactive Agent Host selector
npm run build:renderer	build succeeds	build succeeds	vite build --config apps/desktop/vite.config.ts built in 12.40s

Tests and coverage

• Tests added or changed:
  • apps/desktop/renderer/test/TurnPanel.test.tsx: Added #322 renders EngineSelect for an unlocked position and EngineBadge when locked.
  • apps/desktop/renderer/test/conversation-interaction.test.tsx: Separated locked (true/undefined) assertions from unlocked (false) interactive assertions.
  • apps/desktop/renderer/test/App.test.tsx: Added #322 opens an unlocked employee direct conversation with an interactive Agent Host selector and aligned persisted binding tests with agentLocked: true.
• Coverage before / after, when measured: N/A
• Intentionally uncovered behavior and reason: None.

Change classification

• User-visible behavior
• Internal refactor or maintenance
• Documentation only
• Build, CI, dependency, or repository configuration
• Breaking change
• Security-sensitive change

Risk and rollback

• Risk level and affected components: Low; scoped strictly to renderer conversation header rendering in TurnPanel.tsx.
• Compatibility, migration, privacy, performance, or operational impact: Restores backward compatibility for imported employees per PR feat(runtime): lock initial Agent selection #289. No API or schema changes.
• Rollback procedure: git revert this commit.

Breaking or security notes

None

Author checklist

• A maintainer confirmed that the linked issue or tracking record was ready before implementation began, or the automation was pre-authorized under GOVERNANCE.md.
• This branch was created from an up-to-date default branch and contains no unrelated changes.
• I ran the repository's applicable tests, lint, type checks, builds, coverage, and security checks.
• I added a regression test for a bug fix, or explained why one is impractical.
• I updated relevant documentation and changelog files.
• I reviewed the diff for secrets, personal data, generated artifacts, and dependency risk.
• The PR is ready for CI and review by someone other than the sole author.
• All reported results are reproducible.

Reviewer notes

Extra scrutiny should focus on:

1. Verifying that locked employees (engineLocked: true) continue to display the fixed <EngineBadge> without dropdown affordances.
2. Verifying that unlocked employees (engineLocked: false) display <EngineSelect>, and once selected, transition permanently to the locked badge.