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, 30 insertions, 0 deletions

diff --git a/tests/Agent.Core.Tests/ConfigurationTests.cs b/tests/Agent.Core.Tests/ConfigurationTests.cs
index 64b2d85..e588825 100644
--- a/tests/Agent.Core.Tests/ConfigurationTests.cs
+++ b/tests/Agent.Core.Tests/ConfigurationTests.cs
@@ -37,6 +37,36 @@ public sealed class ConfigurationTests
         Assert.Throws<ConfigurationException>(() => ConfigurationLoader.Load(config));
     }
 
+    [Theory]
+    [InlineData("true")]
+    [InlineData("false")]
+    [InlineData("low")]
+    [InlineData("medium")]
+    [InlineData("high")]
+    [InlineData("max")]
+    public void Ollama_think_accepts_native_boolean_and_level_values(string value)
+    {
+        using var directory = new TestDirectory();
+        string config = CreateValidConfiguration(directory);
+        System.IO.File.WriteAllText(config, System.IO.File.ReadAllText(config).Replace("  model: model", $"  model: model\n  think: {value}", StringComparison.Ordinal));
+
+        AgentConfiguration result = ConfigurationLoader.Load(config);
+
+        Assert.Equal(value is "true" or "false" ? bool.Parse(value) : value, result.Ollama.Think);
+    }
+
+    [Fact]
+    public void Ollama_think_rejects_unknown_level()
+    {
+        using var directory = new TestDirectory();
+        string config = CreateValidConfiguration(directory);
+        System.IO.File.WriteAllText(config, System.IO.File.ReadAllText(config).Replace("  model: model", "  model: model\n  think: extreme", StringComparison.Ordinal));
+
+        ConfigurationException error = Assert.Throws<ConfigurationException>(() => ConfigurationLoader.Load(config));
+
+        Assert.Contains("ollama.think", error.Message, StringComparison.Ordinal);
+    }
+
     [Fact]
     public void CommandLineLanguageOverrideIsCaptured()
     {