fix(tess): redact chat persistence and egress (#725)

apps/gateway/src/commands/command-executor.service.ts

@@ -435,22 +435,28 @@ export class CommandExecutorService {
           };
         }
         const pollToken = crypto.randomUUID();
-        const key = `mosaic:auth:poll:${pollToken}`;
-        // Store pending state in Valkey (TTL 5 minutes)
+        const tokenDigest = await crypto.subtle.digest(
+          'SHA-256',
+          new TextEncoder().encode(pollToken),
+        );
+        const tokenHash = Array.from(new Uint8Array(tokenDigest), (byte: number): string =>
+          byte.toString(16).padStart(2, '0'),
+        ).join('');
+        const key = `mosaic:auth:poll:${tokenHash}`;
+        // Persist only a short-lived token digest. The raw token is delivered only by
+        // the authenticated dashboard flow, never in chat output or command metadata.
         await this.redis.set(
           key,
           JSON.stringify({ status: 'pending', provider: providerName, userId }),
           'EX',
           300,
         );
-        // In production this would construct an OAuth URL
-        const loginUrl = `${process.env['MOSAIC_BASE_URL'] ?? 'http://localhost:3000'}/auth/provider/${providerName}?token=${pollToken}`;
         return {
           command: 'provider',
           success: true,
-          message: `Open this URL to authenticate with ${providerName}:\n${loginUrl}`,
+          message: `Provider login for ${providerName} is ready. Continue in the authenticated dashboard.`,
           conversationId,
-          data: { loginUrl, pollToken, provider: providerName },
+          data: { provider: providerName },
         };
       }