fix: wizard preview TLS, progress storage and inactive bot logs (#2651)

src/langbot/pkg/api/http/service/bot.py

@@ -776,7 +776,8 @@ class BotService:
             raise WorkspaceNotFoundError('Bot not found')
         runtime_bot = await self.ap.platform_mgr.get_bot_by_uuid(context, bot_uuid)
         if runtime_bot is None:
-            raise Exception('Bot not found')
+            # Saved but disabled/unconfigured bots have no runtime logs yet.
+            return [], 0
 
         logs, total_count = await runtime_bot.logger.get_logs(from_index, max_count)
 

src/langbot/pkg/entity/persistence/metadata.py

@@ -9,7 +9,7 @@ class Metadata(Base):
     __tablename__ = 'metadata'
 
     key = sqlalchemy.Column(sqlalchemy.String(255), primary_key=True)
-    value = sqlalchemy.Column(sqlalchemy.String(255))
+    value = sqlalchemy.Column(sqlalchemy.Text())
 
 
 class WorkspaceMetadata(Base):
@@ -23,4 +23,4 @@ class WorkspaceMetadata(Base):
         primary_key=True,
     )
     key = sqlalchemy.Column(sqlalchemy.String(255), primary_key=True)
-    value = sqlalchemy.Column(sqlalchemy.String(255))
+    value = sqlalchemy.Column(sqlalchemy.Text())

src/langbot/pkg/persistence/alembic/versions/0037_metadata_text.py

@@ -0,0 +1,22 @@
+"""Allow structured wizard progress in metadata values."""
+
+from alembic import op
+import sqlalchemy as sa
+
+revision = '0037_metadata_text'
+down_revision = '0036_execution_host_leases'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    inspector = sa.inspect(op.get_bind())
+    for table in ('metadata', 'workspace_metadata'):
+        if inspector.has_table(table):
+            with op.batch_alter_table(table) as batch:
+                batch.alter_column('value', existing_type=sa.String(255), type_=sa.Text(), existing_nullable=True)
+
+
+def downgrade():
+    # Keep the widened type: narrowing would destroy valid saved progress.
+    pass

src/langbot/templates/embed/widget.js

@@ -174,6 +174,17 @@
     bubbleIcon: "__LANGBOT_BUBBLE_ICON__",
   };
 
+  // Wizard previews must use the browser-visible backend URL. Behind a TLS
+  // proxy the server's request URL can be HTTP even when widget.js uses HTTPS.
+  // External embeds retain their configured public webhook prefix.
+  if (scriptEl && scriptEl.src) {
+    var scriptUrl = new URL(scriptEl.src, document.baseURI);
+    if (scriptUrl.searchParams.get("preview") === "wizard") {
+      CONFIG.baseUrl = scriptUrl.origin;
+      CONFIG.logoUrl = CONFIG.baseUrl + "/api/v1/embed/logo";
+    }
+  }
+
   // ========== Styles ==========
   var STYLES =
     '\