refactor(agents): move tools package to app/agents/shared (slice 6)

Relocate the entire new_chat/tools/ package (62 files incl. registry, hitl, MCP
cluster, and all connector subpackages: gmail/slack/discord/teams/drive/etc.)
to the shared kernel. The package turned out to be a clean cohesive cluster:
its only references to non-tools new_chat modules were comments, and its
middleware deps were already flipped to shared in slice 5c.

Flip 33 live importers (multi-agent, flows, routes, services, anonymous_agent,
tests). Re-export shims remain for the frozen single-agent stack: a package
__init__ mirroring the public surface (new_chat.__init__ imports it) plus
invalid_tool + registry submodule shims (chat_deepagent imports those).

Resolves slice 5c's two transient back-edges: shared/middleware/action_log
(TYPE_CHECKING ToolDefinition) and tool_call_repair (local INVALID_TOOL_NAME)
now point at app.agents.shared.tools.

surfsense_backend/app/agents/shared/tools/video_presentation.py

@@ -0,0 +1,138 @@
+"""
+Video presentation generation tool for the SurfSense agent.
+
+This module provides a factory function for creating the generate_video_presentation
+tool that submits a Celery task for background video presentation generation. The
+tool then polls the row until it reaches a terminal status (READY/FAILED) and
+returns that status. The wait is bounded by the chat's HTTP / process lifetime;
+see app.agents.shared.deliverable_wait for details.
+"""
+
+import logging
+from typing import Any
+
+from langchain_core.tools import tool
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.agents.shared.deliverable_wait import wait_for_deliverable
+from app.db import VideoPresentation, VideoPresentationStatus, shielded_async_session
+
+logger = logging.getLogger(__name__)
+
+
+def create_generate_video_presentation_tool(
+    search_space_id: int,
+    db_session: AsyncSession,
+    thread_id: int | None = None,
+):
+    """
+    Factory function to create the generate_video_presentation tool with injected dependencies.
+
+    Pre-creates video presentation record with pending status so the ID is available
+    immediately for frontend polling. The row is written via a fresh, tool-local
+    session so parallel tool calls (e.g. video + podcast in the same agent step)
+    don't share an ``AsyncSession`` (which is not concurrency-safe).
+    """
+    del db_session  # writes use a fresh tool-local session, see below
+
+    @tool
+    async def generate_video_presentation(
+        source_content: str,
+        video_title: str = "SurfSense Presentation",
+        user_prompt: str | None = None,
+    ) -> dict[str, Any]:
+        """Generate a video presentation from the provided content.
+
+        Use this tool when the user asks to create a video, presentation, slides, or slide deck.
+
+        Args:
+            source_content: The text content to turn into a presentation.
+            video_title: Title for the presentation (default: "SurfSense Presentation")
+            user_prompt: Optional style/tone instructions.
+        """
+        try:
+            # See podcast.py for the rationale: parallel tool calls share the
+            # streaming session, and AsyncSession is not concurrency-safe —
+            # interleaved flushes produce "Session.add() during flush" and
+            # poison the transaction for every concurrent tool.
+            async with shielded_async_session() as session:
+                video_pres = VideoPresentation(
+                    title=video_title,
+                    status=VideoPresentationStatus.PENDING,
+                    search_space_id=search_space_id,
+                    thread_id=thread_id,
+                )
+                session.add(video_pres)
+                await session.commit()
+                await session.refresh(video_pres)
+                video_pres_id = video_pres.id
+
+            from app.tasks.celery_tasks.video_presentation_tasks import (
+                generate_video_presentation_task,
+            )
+
+            task = generate_video_presentation_task.delay(
+                video_presentation_id=video_pres_id,
+                source_content=source_content,
+                search_space_id=search_space_id,
+                user_prompt=user_prompt,
+            )
+
+            logger.info(
+                "[generate_video_presentation] Created video presentation %s, task: %s",
+                video_pres_id,
+                task.id,
+            )
+
+            # Wait until the Celery worker flips the row to a terminal
+            # state. No internal budget — see deliverable_wait module.
+            terminal_status, _columns, elapsed = await wait_for_deliverable(
+                model=VideoPresentation,
+                row_id=video_pres_id,
+                columns=[VideoPresentation.status],
+                terminal_statuses={
+                    VideoPresentationStatus.READY,
+                    VideoPresentationStatus.FAILED,
+                },
+            )
+
+            if terminal_status == VideoPresentationStatus.READY:
+                logger.info(
+                    "[generate_video_presentation] %s READY in %.2fs",
+                    video_pres_id,
+                    elapsed,
+                )
+                return {
+                    "status": VideoPresentationStatus.READY.value,
+                    "video_presentation_id": video_pres_id,
+                    "title": video_title,
+                    "message": "Video presentation generated and saved.",
+                }
+
+            # Only other terminal state is FAILED.
+            logger.warning(
+                "[generate_video_presentation] %s FAILED in %.2fs",
+                video_pres_id,
+                elapsed,
+            )
+            return {
+                "status": VideoPresentationStatus.FAILED.value,
+                "video_presentation_id": video_pres_id,
+                "title": video_title,
+                "error": (
+                    "Background worker reported FAILED status for this "
+                    "video presentation."
+                ),
+            }
+
+        except Exception as e:
+            error_message = str(e)
+            logger.exception("[generate_video_presentation] Error: %s", error_message)
+            return {
+                "status": VideoPresentationStatus.FAILED.value,
+                "error": error_message,
+                "title": video_title,
+                "video_presentation_id": None,
+            }
+
+    return generate_video_presentation