refactor: align Java SDK with Python SDK v0.2.0

  Major refactoring to match Python SDK structure:
  - Refactor file structure and API design
  - Add Config, Version classes
  - Refactor Client to use Map instead of custom objects
  - Add comprehensive test suite (27 tests, 100% pass)
  - Update GitHub Actions workflows
  - Remove OpenAPI generated code
  - Fix WaveSpeed.java -> Wavespeed.java rename
  - Update version to 0.2.0

  Breaking changes:
  - Client API now returns Map<String, Object> instead of Prediction objects
  - Module-level API via Wavespeed class (static methods)
  - New configuration system via Config.api

  🤖 Generated with Claude Code

Author: Leeon-Tang

src/main/java/ai/wavespeed/WaveSpeed.java src/main/java/ai/wavespeed/Wavespeed.javasrc/main/java/ai/wavespeed/WaveSpeed.java renamed to src/main/java/ai/wavespeed/Wavespeed.java

@@ -51,7 +51,7 @@ void testVersionAccess() {
         // Test version access
         String version = Wavespeed.version();
         assertNotNull(version);
-        assertEquals("0.1.0", version);
+        assertEquals("0.2.0", version);
     }
 
     @Test