Add detailed block-level diagnostic logging for prompt build

Logs all block names/roles/enabled status at loop entry, user-block
content lengths before sanitization, and final execution message counts
to pinpoint exactly where user-role blocks disappear.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

prompt-builder.js

@@ -1098,6 +1098,12 @@ export async function buildTaskPrompt(settings = {}, taskType, context = {}) {
   let assistantRoleBlockCount = 0;
   let systemRoleBlockCount = 0;
 
+  console.log(
+    `[ST-BME][prompt-diag] buildTaskPrompt: taskType=${taskType}, ` +
+      `total blocks=${blocks.length}, ` +
+      `block roles=[${blocks.map((b) => `${b.name}(${b.role},${b.enabled !== false ? "on" : "off"})`).join(", ")}]`,
+  );
+
   for (const block of blocks) {
     if (!block || block.enabled === false) continue;
 
@@ -1118,6 +1124,15 @@ export async function buildTaskPrompt(settings = {}, taskType, context = {}) {
       content = interpolateVariables(block.content || "", resolvedContext);
     }
 
+    if (role === "user") {
+      console.log(
+        `[ST-BME][prompt-diag] user block "${block.name || block.id}": ` +
+          `type=${block.type}, contentLen=${String(content || "").length}, ` +
+          `rawContentLen=${String(block.content || "").length}, ` +
+          `blockedContentsCount=${worldInfoRuntimeBlockedContents.length}`,
+      );
+    }
+
     const sanitizedBlockContent = sanitizeTaskPromptText(
       settings,
       taskType,
@@ -1205,6 +1220,13 @@ export async function buildTaskPrompt(settings = {}, taskType, context = {}) {
     }
   }
 
+  console.log(
+    `[ST-BME][prompt-diag] buildTaskPrompt done: ` +
+      `executionMessages=${executionMessages.length}, ` +
+      `userBlocks=${userRoleBlockCount}, systemBlocks=${systemRoleBlockCount}, ` +
+      `customMessages=${customMessages.length}`,
+  );
+
   for (const message of worldInfoResolution.additionalMessages || []) {
     const executionMessage = createExecutionMessage(
       message.role,