fix(newos4): chat() threw on every tool-using turn and never returned its answer

Regression from 32608bc, caught by the .chat() caller sweep before it aged:

- `recent` was referenced in chat()'s finally block but never declared, so any
  turn with toolTurns > 0 threw ReferenceError there and chat() REJECTED.
  delegateTask's catch turned that into "agent failed"; the 'completed'
  fallback was only ever reachable on tool-free turns.
- chat() still had no return at all, so a tool-free turn resolved undefined and
  module-orchestrator.js:1250 fell through to `|| 'completed'`.

Both fixed: `const recent` is now built from _toolCallLog, and chat() returns
{ content: finalAnswer, toolTurns } before the archive block (a return at the
end of the method would let _archiveSession swallow the answer).

Verified with /tmp/probe-chat-hotfix.js, 6/6: tool-using turn resolves
{content:'WORKER ANSWER', toolTurns:2}, tool-free turn resolves the answer,
the orchestrator's own projection returns the answer instead of 'completed',
and _chatLock is released. Run against 32608bc the same probe says
"recent is not defined" - i.e. it reproduces the shipped defect.

Not included: the _chatLock serialisation (orchestrate-parallel still runs
sub-tasks one at a time and the 10s force-release can clear the main turn's
lock). That stays open in STEER-20261102-201045-ab08.

4 files changed, 20 insertions, 6 deletions

diff --git a/main.html b/main.html
index 5681c10..858a43f 100644
--- a/main.html
+++ b/main.html
@@ -1349,13 +1349,13 @@
     </script>
 
     <!-- v4.5.63: A2A scratchpad fixes + agent-register arg fix -->
-<script src="modules/core/core-bundle.js?v=v4.6.137"></script>
+<script src="modules/core/core-bundle.js?v=v4.6.138"></script>
 
     <!-- Async dependency-ordered module loader now only initializes terminal and loads optional ext modules -->
-<script src="modules/core/module-loader.js?v=v4.6.137"></script>
+<script src="modules/core/module-loader.js?v=v4.6.138"></script>
 
     <!-- Critical ext bundle loads AFTER webx11 exists so registerModule calls work -->
-<script src="modules/ext/critical-ext-bundle.js?v=v4.6.137"></script>
+<script src="modules/ext/critical-ext-bundle.js?v=v4.6.138"></script>
 
 <script>
 // ═══ ONE TRUE VERSION SOURCE ═══
diff --git a/modules/core/core-bundle.js b/modules/core/core-bundle.js
index 56f0c97..ef2d425 100644
--- a/modules/core/core-bundle.js
+++ b/modules/core/core-bundle.js
@@ -9891,13 +9891,20 @@ max_chars: { type: 'integer', description: 'Max characters of page content to re
                     // Log the AI interaction
                     this.terminal.log('INFO', 'AI', 'Query: ' + userMessage.substring(0, 100));
                     if (loopResult && loopResult.toolTurns) {
-                        const toolNames = this._toolCallLog.slice(-(loopResult.toolTurns || 0)).map(function(e) { return e.name; }).join(', ');
+                        // `recent` was referenced but never declared: the bare identifier threw
+                        // ReferenceError inside this finally block, rejecting chat() on every
+                        // tool-using turn (shipped in 32608bc, caught by the caller sweep).
+                        const recent = this._toolCallLog.slice(-(loopResult.toolTurns || 0));
+                        const toolNames = recent.map(function(e) { return e.name; }).join(', ');
                         this.terminal.log('INFO', 'AI', 'Used ' + loopResult.toolTurns + ' tool(s): ' + toolNames
                             + ' · returned ' + Math.round(recent.reduce((a, e) => a + e.returnedBytes, 0) / 1024) + 'KB'
                             + ' · clipped ' + Math.round(recent.reduce((a, e) => a + e.clippedBytes, 0) / 1024) + 'KB'
                             + ' · ' + recent.filter(e => e.truncated).length + ' truncated');
                     }
                 }
+                // Callers (orchestrator delegateTask) need the answer itself, not just the
+                // side effects it left in the session context.
+                return { content: loopResult && loopResult.finalAnswer, toolTurns: (loopResult && loopResult.toolTurns) || 0 };
                 // Auto-archive every 10 messages
                 if (this._messageCount > 0 && this._messageCount % 10 === 0) {
                     this._archiveSession('Auto-archive at message ' + this._messageCount);
diff --git a/modules/core/module-aiassist.js b/modules/core/module-aiassist.js
index 365bf94..417e1b6 100644
--- a/modules/core/module-aiassist.js
+++ b/modules/core/module-aiassist.js
@@ -1016,13 +1016,20 @@ max_chars: { type: 'integer', description: 'Max characters of page content to re
                     // Log the AI interaction
                     this.terminal.log('INFO', 'AI', 'Query: ' + userMessage.substring(0, 100));
                     if (loopResult && loopResult.toolTurns) {
-                        const toolNames = this._toolCallLog.slice(-(loopResult.toolTurns || 0)).map(function(e) { return e.name; }).join(', ');
+                        // `recent` was referenced but never declared: the bare identifier threw
+                        // ReferenceError inside this finally block, rejecting chat() on every
+                        // tool-using turn (shipped in 32608bc, caught by the caller sweep).
+                        const recent = this._toolCallLog.slice(-(loopResult.toolTurns || 0));
+                        const toolNames = recent.map(function(e) { return e.name; }).join(', ');
                         this.terminal.log('INFO', 'AI', 'Used ' + loopResult.toolTurns + ' tool(s): ' + toolNames
                             + ' · returned ' + Math.round(recent.reduce((a, e) => a + e.returnedBytes, 0) / 1024) + 'KB'
                             + ' · clipped ' + Math.round(recent.reduce((a, e) => a + e.clippedBytes, 0) / 1024) + 'KB'
                             + ' · ' + recent.filter(e => e.truncated).length + ' truncated');
                     }
                 }
+                // Callers (orchestrator delegateTask) need the answer itself, not just the
+                // side effects it left in the session context.
+                return { content: loopResult && loopResult.finalAnswer, toolTurns: (loopResult && loopResult.toolTurns) || 0 };
                 // Auto-archive every 10 messages
                 if (this._messageCount > 0 && this._messageCount % 10 === 0) {
                     this._archiveSession('Auto-archive at message ' + this._messageCount);
diff --git a/modules/core/module-loader.js b/modules/core/module-loader.js
index a0be94c..eb916d1 100644
--- a/modules/core/module-loader.js
+++ b/modules/core/module-loader.js
@@ -4,7 +4,7 @@
     // Core module bundle loaded synchronously in main.html.
     // This loader only handles version cache-busting, splash, terminal init, and optional ext modules.
 
-    const LATEST_VER = 'v4.6.137';
+    const LATEST_VER = 'v4.6.138';
     const CACHE = '?v=' + LATEST_VER;
     // Exposed so ext modules can register their own URL with the same cache-busting version
     // instead of an unversioned path the browser may already have cached (shell.js did).