fix(server): add .passthrough() to MCP tool output schemas

[Aarjav Jain (A2rjav)]

Summary

Closes #929

Chrome APIs return extra fields alongside the known fields in their responses. Zod's default strict mode rejects unknown fields, causing MCP tool failures whenever Chrome returns an unexpected key.

Root cause: Zod objects without .passthrough() strip (or in structured-output mode, reject) extra keys. Chrome's tab, window, bookmark, history, tab-group, and console APIs all return fields beyond what the schemas declared.

Changes:

• navigation.ts — .passthrough() on pageInfoSchema (affects get_active_page, list_pages, show_page, move_page)
• windows.ts — .passthrough() on windowInfoSchema + inner bounds object; adds missing incognito field
• tab-groups.ts — .passthrough() on tabGroupWithPageIdsSchema
• bookmarks.ts — .passthrough() on bookmarkNodeSchema
• history.ts — .passthrough() on historyItemSchema
• console.ts — .passthrough() on console entry schema
• browseros_server_updater.cc — removes misplaced LaunchOptions block (belonged in process_controller_impl.cc)
• process_controller_impl.cc — injects BROWSEROS_DIR env var into launched server process (cross-platform)

Test plan

• list_windows returns results including incognito windows without schema error
• list_pages / get_active_page work when Chrome returns extra tab fields
• list_tab_groups returns results without validation failure
• get_bookmarks / search_bookmarks work with Chrome's extra bookmark fields
• search_history / get_recent_history work correctly
• get_console_logs returns entries without schema rejection

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[Aarjav Jain (A2rjav)]

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