Fix strategy switch cash/reserve sync conflict

[Pigbibi]

Why

• When loading account config, cash-only (allow margin) and reserved-cash override can be both detected from backend.
• Sync flow previously set reserve fields first, then cash-only, leaving reserve policy as existing value (ratio/max/floor) while disabling reserve controls.

What changed

• In syncStrategyForAccount, add one-line reconciliation after reserve/cash-only sync to clear reserve override when margin is enabled.
• Regenerated web/strategy-switch-console/app_js.js.
• Added regression coverage in tests/test_cash_financing.js for initial sync mutual-exclusion behavior.

Validation

• node tests/test_cash_financing.js
• node tests/strategy_switch_worker_validation.mjs

[github-actions]

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