chore: use thinking mode

agents/ollama.ts

@@ -119,7 +119,8 @@ async function runOllamaLoop(ctx: AgentRunContext): Promise<AgentResult> {
         tools,
         keep_alive: "10m",
         options: {
-          think: false,
+          think: true,
+          num_ctx: 32768,
         } as Record<string, unknown>,
       });
     } catch (err) {
@@ -206,13 +207,32 @@ async function runOllamaLoop(ctx: AgentRunContext): Promise<AgentResult> {
     // re-calling select_mode instead of executing the workflow.
     if (calledSelectMode && !pendingModeNudge) {
       pendingModeNudge = true;
+
+      // Parse the selected mode name from the tool result so we can give a
+      // more specific first-step instruction.
+      let selectedMode = "";
+      try {
+        const lastToolMsg = messages[messages.length - 1];
+        const parsed = JSON.parse(
+          typeof lastToolMsg.content === "string" ? lastToolMsg.content : "",
+        );
+        if (typeof parsed?.modeName === "string") selectedMode = parsed.modeName;
+      } catch {
+        // best-effort
+      }
+
+      const firstStep =
+        selectedMode === "Review" || selectedMode === "IncrementalReview"
+          ? "Your first tool call must be checkout_pr with the PR number from the event context."
+          : "Call the first tool required by the workflow now.";
+
       messages.push({
         role: "user",
         content:
-          "Good. You have selected a mode and received the workflow. " +
+          `Good. You have selected ${selectedMode || "a"} mode and received the workflow. ` +
           "Do NOT call select_mode again. " +
-          "Call the next tool to execute the workflow now (e.g. checkout_pr, get_issue, create_pull_request_review). " +
-          "Start immediately.",
+          `${firstStep} ` +
+          "Execute the complete workflow step by step until you call create_pull_request_review or report_progress.",
       });
     }
   }