fix: implement native Ollama thinking semantics

Model Ollama chat thinking separately from final content, preserve it only across assistant tool-call continuation, and keep private reasoning out of user results, session context, and logs.

Accept native boolean and low/medium/high/max think values, normalize YAML booleans, and serialize explicit overrides using the native top-level chat field.

Stop forcing think=false for structured planning, skill selection, and context summaries; corrected retries now retain the configured thinking mode.

Update the specification, design, audit report, and requirement traceability for OLL-14.

Add request/response, configuration, observability, retry, and tool-continuation coverage. Verified with 92 passing Agent.Core tests and a deepseek-v4-flash:cloud think:true MCP operational run.

1 files changed, 5 insertions, 2 deletions

diff --git a/tests/Agent.Core.Tests/ObservabilityTests.cs b/tests/Agent.Core.Tests/ObservabilityTests.cs
index 8231ab9..3dcfdf6 100644
--- a/tests/Agent.Core.Tests/ObservabilityTests.cs
+++ b/tests/Agent.Core.Tests/ObservabilityTests.cs
@@ -23,8 +23,8 @@ public sealed class ObservabilityTests
         var context = new AgentLlmCallContext(callId, sessionId, taskId, plannerTaskId, "replan", 7, 2, "model-a");
         using (var observer = new JsonLinesRuntimeObserver(directory.Path, 1024 * 1024, 2))
         {
-            observer.LlmRequest(context, [new OllamaMessage("user", "request")]);
-            observer.LlmResponse(context, new OllamaResult("response", 11, 13));
+            observer.LlmRequest(context, [new OllamaMessage("assistant", "request", Thinking: "private request reasoning")]);
+            observer.LlmResponse(context, new OllamaResult("response", 11, 13, Thinking: "private response reasoning"));
             observer.ToolResult(context, "file_read", new ToolExecutionResult(true, "ok", false));
             observer.LlmFailure(context, "planning_failed", "invalid plan");
         }
@@ -45,6 +45,9 @@ public sealed class ObservabilityTests
         Assert.Equal("file_read", entries[2].GetProperty("tool_name").GetString());
         Assert.Equal("llm.failure", entries[3].GetProperty("event_name").GetString());
         Assert.Equal("planning_failed", entries[3].GetProperty("error_code").GetString());
+        string log = File.ReadAllText(Path.Combine(directory.Path, "llm.jsonl"));
+        Assert.DoesNotContain("private request reasoning", log, StringComparison.Ordinal);
+        Assert.DoesNotContain("private response reasoning", log, StringComparison.Ordinal);
     }
 
     [Fact]