Add Request Browser Electron alternative with OpenCode workspace

[kreates1994]

Summary

• add a branded Request Browser Electron desktop shell around the BrowserOS agent UI and CDP toolchain
• add OpenCode Zen and OpenCode Go ACP provider flows with local encrypted provider persistence
• add local workspace collections, databases, records, sources, assets, research plans, recaps, and MCP tools
• add BrowserOS-compatible Electron bridges for tabs, windows, side panel, storage, scripting, downloads, history, bookmarks, permissions, alarms, and tab groups
• add Windows NSIS packaging and Request Browser application icon

Validation

• desktop and app TypeScript checks pass
• production and development extension builds pass
• Windows NSIS packaging passes
• OpenCode/ACP provider tests: 46 passing across targeted suites
• workspace route/store/MCP tests: 4 passing
• live Electron checks: tabs, Google fallback search, collapsible navigation and assistant panels, OpenCode page-title goal, sidecar health/CDP
• workspace CRUD and asset byte round-trip pass

Notes

• this Electron alternative preserves internal BrowserOS compatibility namespaces intentionally
• full Chromium-fork parity is out of scope: BrowserOS cloud sync/auth, complete MV2/uBlock behavior, password/extension import, and advanced Chrome APIs remain reduced
• branch started from BrowserOS 0.47.12 and will need conflict review against current main (0.47.14)

[github-actions]

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