fix: prevent IndexError in Type action parser and fix screenshot temp file leak

[Ricardo-M-L]

Summary

Two bug fixes:

1. IndexError in parse_action() for Type actions (handler.py:351)

response.split("text=", 1)[1] assumes the response always contains text=. A malformed Type action like do(action="Type") without a text parameter causes IndexError: list index out of range.

Fix: Check split result length before accessing [1], raise clear ValueError.

2. Temp file leak in ADB screenshot capture (screenshot.py:65-85)

Temp files created with UUID names are only cleaned up on the success path (os.remove at line 77). If Image.open(), img.save(), or base64.b64encode() raises an exception, the temp file leaks in /tmp.

Fix: Wrap image processing in try/finally to ensure cleanup regardless of exceptions.

[Ricardo-M-L]

Pushed one more commit (ac3c797) applying the same leak fix to phone_agent/hdc/screenshot.py (the HarmonyOS sibling of the ADB screenshot module). It has the identical try-without-finally pattern — if Image.open() or img.save() raised, the temp screenshot under $TMPDIR was never removed.

The fix mirrors the ADB one exactly:

-        img = Image.open(temp_path)
-        ...
-        os.remove(temp_path)
-        return Screenshot(...)
-    except Exception as e:
-        print(f"Screenshot error: {e}")
-        return _create_fallback_screenshot(...)
+        try:
+            img = Image.open(temp_path)
+            ...
+            return Screenshot(...)
+        finally:
+            if os.path.exists(temp_path):
+                os.remove(temp_path)
+    except Exception as e:
+        print(f"Screenshot error: {e}")
+        if os.path.exists(temp_path):
+            os.remove(temp_path)
+        return _create_fallback_screenshot(...)

Happy to split this into a separate PR if you'd prefer — it keeps the scope narrow ("temp file leak" in both OS paths), so bundling felt natural, but let me know.