chore: re-apply manual patches after regen

Re-apply patches that Fern's regen reverted, and adapt hand-maintained
tests to the new generator output.

ClientOptions.java: restore correct User-Agent/X-Fern-SDK-* headers
(com.deepgram:deepgram-java-sdk, version 0.4.0) and the
// x-release-please-version markers. Fern regen still rewrites these
to the wrong artifact id and strips the version markers.

ReconnectingWebSocketListener.java: restore applyOptionsOverride()
hook, volatile option-derived fields, configurable connectionTimeoutMs
on ReconnectOptions, and the maxRetries(0) "connect once, don't retry"
semantics (retryCount > maxRetries, not >=). Generator regen still
reverts all of these.

Environment.AGENT was removed by the generator (4-arg constructor with
new agentRest field). Hand-maintained tests that referenced
Environment.AGENT now build an equivalent agent-shaped environment via
Environment.custom().agentRest(...).

Author: GregHolmes

.fernignore

@@ -14,15 +14,15 @@ src/main/java/com/deepgram/AsyncDeepgramClientBuilder.java
 # Contains User-Agent, X-Fern-SDK-Name, and X-Fern-SDK-Version headers
 # with // x-release-please-version comments for automated version bumps.
 # Fern regen overwrites these with incorrect SDK names and strips the markers.
-src/main/java/com/deepgram/core/ClientOptions.java.bak
+src/main/java/com/deepgram/core/ClientOptions.java
 
 # Transport abstraction (pluggable transport for SageMaker, etc.)
 src/main/java/com/deepgram/core/transport/
 
 # Bug fixes for maxRetries(0) semantics ("connect once, don't retry") and a
 # configurable connectionTimeoutMs on ReconnectOptions (was hardcoded 4000ms).
 # Pull this back out once the fixes are upstreamed into the Fern generator.
-src/main/java/com/deepgram/core/ReconnectingWebSocketListener.java.bak
+src/main/java/com/deepgram/core/ReconnectingWebSocketListener.java
 
 # Build and project configuration
 build.gradle

src/main/java/com/deepgram/core/ClientOptions.java

@@ -41,10 +41,10 @@ private ClientOptions(
         this.headers.putAll(headers);
         this.headers.putAll(new HashMap<String, String>() {
             {
-                put("User-Agent", "com.deepgram:deepgram-sdk/0.4.1");
+                put("User-Agent", "com.deepgram:deepgram-java-sdk/0.4.0"); // x-release-please-version
                 put("X-Fern-Language", "JAVA");
-                put("X-Fern-SDK-Name", "com.deepgram.fern:api-sdk");
-                put("X-Fern-SDK-Version", "0.4.1");
+                put("X-Fern-SDK-Name", "com.deepgram:deepgram-java-sdk");
+                put("X-Fern-SDK-Version", "0.4.0"); // x-release-please-version
             }
         });
         this.headerSuppliers = headerSuppliers;