Refactor frontend workspaces and centralize API contracts

Organize domain APIs and types under common/apis, shared components under named folders, and private workspace logic alongside each page.

Use Bearer sessions, explicit response envelopes, session-aware routing and streams, and configurable login captcha presentation for the deployed backend contract.

Preserve news, economic calendar, crawler, market, chat, Skills, settings, and demo trading workflows with responsive layouts and explicit configuration saves.

Validate with frontend lint, type checking, 22 test groups, production builds, and deployed desktop/mobile page checks.

web/public/flags/fr.svg

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