Fix poc-agent for vllm/Qwen 3.5: reasoning display, tool parser

- Always display reasoning tokens regardless of reasoning_effort
  setting — Qwen 3.5 thinks natively and the reasoning parser
  separates it into its own field
- Remove chat_template_kwargs that disabled thinking when
  reasoning_effort was "none"
- Add chat_template_kwargs field to ChatRequest for vllm compat
- Update provision script: qwen3_xml tool parser, qwen3 reasoning
  parser, 262K context, 95% GPU memory utilization

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

poc-agent/src/api/openai.rs

@@ -34,6 +34,7 @@ pub async fn stream(
             enabled: reasoning_effort != "none",
             effort: Some(reasoning_effort.to_string()),
         }),
+        chat_template_kwargs: None,
     };
 
     let url = format!("{}/chat/completions", base_url);
@@ -96,14 +97,14 @@ pub async fn stream(
             if let Some(ref r) = choice.delta.reasoning_content {
                 reasoning_chars += r.len();
                 has_reasoning = true;
-                if reasoning_enabled && !r.is_empty() {
+                if !r.is_empty() {
                     let _ = ui_tx.send(UiMessage::Reasoning(r.clone()));
                 }
             }
             if let Some(ref r) = choice.delta.reasoning {
                 reasoning_chars += r.len();
                 has_reasoning = true;
-                if reasoning_enabled && !r.is_empty() {
+                if !r.is_empty() {
                     let _ = ui_tx.send(UiMessage::Reasoning(r.clone()));
                 }
             }
@@ -111,7 +112,7 @@ pub async fn stream(
                 let s = r.to_string();
                 reasoning_chars += s.len();
                 has_reasoning = true;
-                if reasoning_enabled && !s.is_empty() && s != "null" {
+                if !s.is_empty() && s != "null" {
                     let _ = ui_tx.send(UiMessage::Reasoning(s));
                 }
             }

poc-agent/src/types.rs

@@ -129,6 +129,9 @@ pub struct ChatRequest {
     /// - reasoning.effort (documented: "none" disables entirely)
     #[serde(skip_serializing_if = "Option::is_none")]
     pub reasoning: Option<ReasoningConfig>,
+    /// vllm chat template kwargs — used to disable thinking on Qwen 3.5
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub chat_template_kwargs: Option<serde_json::Value>,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]