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.

2 files changed, 6 insertions, 1 deletions

diff --git a/src/Agent.App/Configuration/AgentConfiguration.cs b/src/Agent.App/Configuration/AgentConfiguration.cs
index 362b889..c5f720b 100644
--- a/src/Agent.App/Configuration/AgentConfiguration.cs
+++ b/src/Agent.App/Configuration/AgentConfiguration.cs
@@ -35,7 +35,7 @@ public sealed class OllamaConfiguration
 {
     public string Endpoint { get; set; } = "http://127.0.0.1:11434";
     public string Model { get; set; } = string.Empty;
-    public bool Think { get; set; } = true;
+    public object Think { get; set; } = true;
     public string KeepAlive { get; set; } = "5m";
     public OllamaGenerationOptions Options { get; set; } = new();
     public Dictionary<string, object?> ExtraOptions { get; set; } = new(StringComparer.Ordinal);
diff --git a/src/Agent.App/Configuration/ConfigurationLoader.cs b/src/Agent.App/Configuration/ConfigurationLoader.cs
index efb3db1..26c56e1 100644
--- a/src/Agent.App/Configuration/ConfigurationLoader.cs
+++ b/src/Agent.App/Configuration/ConfigurationLoader.cs
@@ -53,6 +53,11 @@ public static partial class ConfigurationLoader
         if (value.Agent.MaxIterations <= 0 || value.Agent.SameFailureLimit <= 0) Throw("agent iteration limits must be positive.");
         if (!Uri.TryCreate(value.Ollama.Endpoint, UriKind.Absolute, out Uri? endpoint) || endpoint.Scheme is not ("http" or "https")) Throw("ollama.endpoint must be an absolute HTTP(S) URI.");
         if (string.IsNullOrWhiteSpace(value.Ollama.Model)) Throw("ollama.model is required.");
+        if (value.Ollama.Think is string booleanText && bool.TryParse(booleanText, out bool booleanThink))
+            value.Ollama.Think = booleanThink;
+        if (value.Ollama.Think is not bool &&
+            (value.Ollama.Think is not string thinkLevel || thinkLevel is not ("low" or "medium" or "high" or "max")))
+            Throw("ollama.think must be true, false, low, medium, high, or max.");
         if (value.Ollama.Options.NumCtx is <= 0) Throw("ollama.options.num_ctx must be positive.");
         if (value.Ollama.Options.Temperature is < 0 or > 2) Throw("ollama.options.temperature must be in 0..2.");
         if (value.Planner.MaxTasks is < 1 or > 32) Throw("planner.max_tasks must be in 1..32.");