fix: handle bare numeric and negative durations in Wait action handler

[nankingjing]

Summary

Fixes a bug in ActionHandler._handle_wait where the Wait action silently failed when the model returned a bare numeric duration (int/float) instead of a string like "3 seconds".

Root cause

_handle_wait always calls .replace("seconds", "") on action.get("duration"). When a model emits do(action="Wait", duration=3), ast.literal_eval returns the integer 3. Calling .replace() on an int raises AttributeError, which the except ValueError clause does not catch, so the action falls through to execute()'s generic handler and reports success=False with Action failed: 'int' object has no attribute 'replace' — no actual wait happens. A negative duration string (e.g. "-5 seconds") is a second latent defect: it parses to -5.0 and time.sleep(-5.0) raises ValueError.

Fix (phone_agent/actions/handler.py)

• Check isinstance(duration_raw, (int, float)) before calling string methods; convert numeric input to float directly.
• Broaden the exception clause to except (ValueError, TypeError).
• Clamp negative durations to 1.0 so time.sleep cannot raise.

The documented happy path duration="N seconds" is unchanged.

Test (tests/test_wait_action.py)

Seven deterministic tests driving ActionHandler.execute, covering: string with unit, string without unit, missing key (default), bare int (the bug), bare float, unparseable fallback, and negative clamp. time.sleep is patched — no device or network access.

Verification

• No other open PR touches _handle_wait (checked 修复parse_action函数：移除</answer>标签导致的语法解析错误 #347, fix: prevent IndexError in Type action parser and fix screenshot temp file leak #394, fix: fail malformed model actions #402, Adding log snapshot and action record features #385).
• Independent of the Type-parser IndexError fix (fix: prevent IndexError in Type action parser and fix screenshot temp file leak #394) and the malformed-action fail-on-parse change (fix: fail malformed model actions #402); new test file name avoids collision with test: add unit tests for parse_action and action helpers #410's tests/test_handler.py.

[nankingjing]

Reviewed — isinstance check before .replace and the negative clamp are both correct, and the tests cover int/float/string/missing/negative. Ready for review.

[nankingjing]

Pushed an additional commit to clamp non-finite durations (NaN/inf) to the default 1 s. time.sleep accepts them as valid arguments, but NaN produces no wait and inf would hang the agent. Added regression tests for NaN, inf, and zero-second waits.