Feat/space cta optimization (#2089)

* feat(wizard): persist wizard progress to backend for session resumption

Store wizard step, selected adapter, created bot UUID, and runner
selection in the metadata table. On revisit, the wizard restores
progress and verifies the bot still exists. Progress is cleared
automatically when the wizard is completed or skipped.

* feat(dynamic-form): optimize LLM model selection with space login CTA and improve localization strings

* feat(web): add LangBot Cloud CTA for webhook URL fields in community edition

Show a subtle hint below webhook URL fields prompting users about
LangBot Cloud's public endpoint, only visible in community edition.
Covers all 8 webhook-based adapters with i18n support (4 locales).

src/langbot/pkg/api/http/controller/groups/system.py

@@ -1,3 +1,5 @@
+import json
+
 import quart
 import sqlalchemy
 
@@ -11,16 +13,21 @@ class SystemRouterGroup(group.RouterGroup):
     async def initialize(self) -> None:
         @self.route('/info', methods=['GET'], auth_type=group.AuthType.NONE)
         async def _() -> str:
-            # Read wizard_status from metadata table
-            # Possible values: 'skipped', 'completed'; absent key means 'none'
+            # Read wizard_status and wizard_progress from metadata table
             wizard_status = 'none'
+            wizard_progress = None
             try:
                 result = await self.ap.persistence_mgr.execute_async(
-                    sqlalchemy.select(Metadata).where(Metadata.key == 'wizard_status')
+                    sqlalchemy.select(Metadata).where(Metadata.key.in_(['wizard_status', 'wizard_progress']))
                 )
-                row = result.first()
-                if row:
-                    wizard_status = row.value
+                for row in result:
+                    if row.key == 'wizard_status':
+                        wizard_status = row.value
+                    elif row.key == 'wizard_progress':
+                        try:
+                            wizard_progress = json.loads(row.value)
+                        except (json.JSONDecodeError, TypeError):
+                            wizard_progress = None
             except Exception:
                 pass
 
@@ -43,12 +50,13 @@ class SystemRouterGroup(group.RouterGroup):
                     ),
                     'limitation': self.ap.instance_config.data.get('system', {}).get('limitation', {}),
                     'wizard_status': wizard_status,
+                    'wizard_progress': wizard_progress,
                 }
             )
 
         @self.route('/wizard/completed', methods=['POST'], auth_type=group.AuthType.USER_TOKEN)
         async def _() -> str:
-            """Mark wizard status in metadata table.
+            """Mark wizard status in metadata table and clear progress.
 
             Accepts JSON body: { "status": "skipped" | "completed" }
             """
@@ -69,11 +77,44 @@ class SystemRouterGroup(group.RouterGroup):
                     await self.ap.persistence_mgr.execute_async(
                         sqlalchemy.insert(Metadata).values(key='wizard_status', value=status)
                     )
+
+                # Clear wizard progress when wizard is completed/skipped
+                await self.ap.persistence_mgr.execute_async(
+                    sqlalchemy.delete(Metadata).where(Metadata.key == 'wizard_progress')
+                )
             except Exception as e:
                 return self.http_status(500, 500, f'Failed to update wizard status: {e}')
 
             return self.success(data={})
 
+        @self.route('/wizard/progress', methods=['PUT'], auth_type=group.AuthType.USER_TOKEN)
+        async def _() -> str:
+            """Save wizard progress to metadata table.
+
+            Accepts JSON body with wizard state fields:
+            { "step": int, "selected_adapter": str|null, "created_bot_uuid": str|null,
+              "bot_saved": bool, "selected_runner": str|null }
+            """
+            data = await quart.request.get_json(silent=True) or {}
+            progress_json = json.dumps(data, ensure_ascii=False)
+
+            try:
+                result = await self.ap.persistence_mgr.execute_async(
+                    sqlalchemy.select(Metadata).where(Metadata.key == 'wizard_progress')
+                )
+                if result.first():
+                    await self.ap.persistence_mgr.execute_async(
+                        sqlalchemy.update(Metadata).where(Metadata.key == 'wizard_progress').values(value=progress_json)
+                    )
+                else:
+                    await self.ap.persistence_mgr.execute_async(
+                        sqlalchemy.insert(Metadata).values(key='wizard_progress', value=progress_json)
+                    )
+            except Exception as e:
+                return self.http_status(500, 500, f'Failed to save wizard progress: {e}')
+
+            return self.success(data={})
+
         @self.route('/tasks', methods=['GET'], auth_type=group.AuthType.USER_TOKEN)
         async def _() -> str:
             task_type = quart.request.args.get('type')