fix(desktop): resolve shell bootstrap hasShell=false smoke regression

[Whiteks1]

Issue

Shell bootstrap/initialization is failing with shellReady: false and hasShell=false, causing smoke test failures in both smoke:fallback and smoke:real-path modes.

Observed Failure

Both smoke tests fail with:

{
  "shellReady": false,
  "hasShell": false,
  "happyPathRunDetailReady": false,
  "happyPathArtifactsReady": false,
  "error": "run detail unavailable (activeId=..., hasTabsBar=true, hasShell=false)"
}

Impact

• Run Detail surface unavailable
• Artifacts surface unavailable
• Shell navigation incomplete
• Smoke tests blocked on origin/main (post-desktop(migration): run detail and artifact explorer native surfaces #409)

Root Cause Analysis

The failure is upstream of MainContent routing logic:

• Not a regression from desktop(migration): paper ops, system, and experiments native surfaces #410 (confirmed identical failure on both branches)
• Likely introduced during desktop(migration): run detail and artifact explorer native surfaces #409 native run detail migration work
• Located in shell initialization/bootstrap phase, not surface rendering

Files Likely Involved

• desktop/main/ (main process initialization)
• Shell renderer bootstrap code
• Shell component initialization

Resolution Scope

1. Identify exactly which desktop(migration): run detail and artifact explorer native surfaces #409 change broke shell initialization
2. Fix shell bootstrap to restore shellReady: true and hasShell: true
3. Verify smoke tests pass with all surfaces available
4. Unblock desktop(migration): run detail and artifact explorer native surfaces #409 and desktop(migration): paper ops, system, and experiments native surfaces #410 product work

Blocking

• desktop(migration): run detail and artifact explorer native surfaces #409: Desktop native Run Detail and Artifact Explorer (WIP checkpoint on feat/desktop-native-run-detail)
• desktop(migration): paper ops, system, and experiments native surfaces #410: Desktop Paper Ops, System, Experiments native surfaces (PR feat(desktop): migrate Paper Ops, System, Experiments to native-hosted surfaces (#410) #426, blocked by this shell issue)

DoD

• Shell bootstrap completes successfully
• shellReady: true in smoke tests
• hasShell: true in happy-path checks
• npm run smoke:fallback passes
• npm run smoke:real-path passes
• Run Detail and Artifacts surfaces render without errors