fix: align discussion workspace and tool schemas

test/register-tools.test.ts

@@ -5,6 +5,7 @@ import { registerDirigentTools } from '../plugin/tools/register-tools.ts';
 
 type RegisteredTool = {
   name: string;
+  parameters?: Record<string, unknown>;
   handler: (params: Record<string, unknown>, ctx?: Record<string, unknown>) => Promise<any>;
 };
 
@@ -62,6 +63,7 @@ test('plain private channel create works unchanged without discussion params', a
 
     const tool = api.tools.get('dirigent_discord_control');
     assert.ok(tool);
+    assert.ok(tool!.parameters);
 
     const result = await tool!.handler({
       action: 'channel-private-create',
@@ -100,6 +102,7 @@ test('private channel create rejects callbackChannelId without discussGuide', as
 
   const tool = api.tools.get('dirigent_discord_control');
   assert.ok(tool);
+  assert.ok(tool!.parameters);
 
   const result = await tool!.handler({
     action: 'channel-private-create',
@@ -142,6 +145,7 @@ test('discussion-mode channel create initializes discussion metadata', async ()
 
     const tool = api.tools.get('dirigent_discord_control');
     assert.ok(tool);
+    assert.ok(tool!.parameters);
 
     const result = await tool!.handler({
       action: 'channel-private-create',
@@ -152,6 +156,7 @@ test('discussion-mode channel create initializes discussion metadata', async ()
     }, {
       agentId: 'agent-a',
       sessionKey: 'session-a',
+      workspaceRoot: '/workspace/agent-a',
     });
 
     assert.equal(result.isError, undefined);
@@ -162,6 +167,7 @@ test('discussion-mode channel create initializes discussion metadata', async ()
       originChannelId: 'origin-1',
       initiatorAgentId: 'agent-a',
       initiatorSessionId: 'session-a',
+      initiatorWorkspaceRoot: '/workspace/agent-a',
       discussGuide: 'Decide the callback contract.',
     });
   } finally {
@@ -190,6 +196,7 @@ test('discuss-callback registers and forwards channel/session/agent context', as
 
   const tool = api.tools.get('discuss-callback');
   assert.ok(tool);
+  assert.ok(tool!.parameters);
 
   const result = await tool!.handler({ summaryPath: 'plans/summary.md' }, {
     channelId: 'discussion-1',