feat: add persistent desktop sidebar routes

[ksamaschke]

Summary

• replace main-window tab navigation with persistent sidebar routes for Workspace, Sources, Hooks, and Reports
• keep Settings as a dedicated window while exposing a minimal Sources summary route in the main shell
• extract shared desktop route metadata and add focused route-shell regression coverage

Changes

• add RED coverage for persistent sidebar route requirements
• implement sidebar navigation and route-specific main-window content for workspace, sources, hooks, and reports
• clean up route helper primitives and remove obsolete tab-strip CSS/state

Test Plan

• npm run build:quick
• node --test dist/tests/installer/desktop-sidebar-routes-red-phase.test.js dist/tests/installer/desktop-shell-ux.test.js dist/tests/installer/desktop-shell-frame-red-phase.test.js dist/tests/installer/desktop-settings-window-red-phase.test.js dist/tests/installer/control-plane-client.test.js dist/tests/installer/desktop-dashboard-build.test.js

[ksamaschke]

ICA-REVIEW
ICA-REVIEW-RECEIPT
Reviewer-Stage: 3 (temp checkout)
Reviewer-Agent: reviewer (subagent)
PR: #253
Base: dev
Head-SHA: eda4705
Date-UTC: 2026-03-15T06:37:12Z

Findings: 0
NO FINDINGS

Checks/Tests:

• npm run build:quick (PASS)
• node --test dist/tests/installer/desktop-sidebar-routes-red-phase.test.js dist/tests/installer/desktop-shell-ux.test.js dist/tests/installer/desktop-shell-frame-red-phase.test.js dist/tests/installer/desktop-settings-window-red-phase.test.js dist/tests/installer/control-plane-client.test.js dist/tests/installer/desktop-dashboard-build.test.js (PASS)

Notes:

• Temp checkout validation used a fresh clone of the PR branch with shared local dependencies.

Result: PASS

[ksamaschke]

ICA-SECURITY-REVIEW
ICA-SECURITY-REVIEW-RECEIPT
Security-Reviewer-Stage: post-pr (temp checkout)
Security-Reviewer-Agent: security reviewer (subagent)
Security-Reviewer-Execution: dedicated-security-subagent
Security-Reviewer-Executor: github:ksamaschke
Security-Reviewer-Run-ID: sec-20260315T063712Z-eda470587ed0
PR: #253
Base: dev
Head-SHA: eda4705
Date-UTC: 2026-03-15T06:37:12Z

Findings: 0
NO FINDINGS

Result: PASS