add dollar-cost averaging strategy

[CRF1408]

Adds a simple example demonstrating a DCA trading loop, showing how to use the client to select a market and repeatedly place small orders.

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Note

Introduces a minimal DCA strategy example demonstrating periodic order placement flow.

• New agents/examples/dca_strategy.py uses Polymarket client to fetch markets and pick the target via min(..., key=lambda m: m.spread)
• Configurable amount_per_purchase and interval_seconds; runs an infinite loop printing intended buys (placeholder for client.place_order(...))

^{Written by Cursor Bugbot for commit a7f444a. This will update automatically on new commits. Configure here.}

[cursor]

Accessing non-existent ticker attribute on SimpleMarket

The SimpleMarket class returned by get_all_markets() doesn't have a ticker attribute. The class has id, question, spread, outcomes, etc., but no ticker field. Accessing target.ticker will raise an AttributeError at runtime, preventing the script from executing. A valid identifier like question or id should be used instead.

 

[cursor]

Calling min() on potentially empty markets list

The get_all_markets() method can return an empty list if the API call fails (non-200 status code) or if all market parsing fails. Calling min() on an empty sequence raises a ValueError. The code lacks a check for this scenario before selecting the target market.