Add clip_range compatibility to PPOConfig

[Navy10021]

Motivation

• utils/hp_search.py and tests pass clip_range into PPOConfig, but the PPOConfig dataclass only exposed clip_eps, causing TypeError: PPOConfig.__init__() got an unexpected keyword argument 'clip_range' during HP search runs.
• Provide a backward-compatible bridge so existing callers that use clip_range continue to work without changing other code.

Description

• Added an optional clip_range: Optional[float] = None field to PPOConfig in rl_agent/blue_agent.py to accept legacy callers that pass clip_range.
• Implemented __post_init__ on PPOConfig to synchronize clip_range and clip_eps so either name can be used interchangeably at construction time.
• Change is contained in rl_agent/blue_agent.py and preserves existing clip_eps behavior when clip_range is not provided.

Testing

• Ran pytest -q tests/test_hp_search.py and it passed (7 passed).
• Ran the full test suite with pytest -q and it succeeded (143 passed, 1 skipped).

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Codex Task