Refactor tests for execution plan and add comprehensive storage tests

- Updated `TestModuleSingletons` in `test_execution_plan.py` to reflect new agent templates and playbook names.
- Changed assertions in playbook tests to match updated templates and agents.
- Introduced `test_storage.py` to cover the storage layer, including encryption, BlobStore, and VectorStore functionalities.
- Added tests for S3 interactions, ensuring upload, download, delete, and list operations work as expected.
- Implemented mock tests for Pinecone and Qdrant vector stores to validate upsert, search, and delete operations.

app/agents/checkpoint_agent.py

@@ -0,0 +1,122 @@
+"""Checkpoint agent — project milestone management (list, create, update, delete)."""
+
+from __future__ import annotations
+
+import json
+from typing import Any
+
+from langchain_core.messages import HumanMessage, SystemMessage
+from langchain_core.tools import tool
+from langchain_openai import ChatOpenAI
+
+from app.config.settings import settings
+from app.core.agent_registry import ChatAgent, registry
+
+_SYSTEM_PROMPT = (
+    "You are a project checkpoint assistant. Checkpoints are milestone dates that\n"
+    "track progress on a project — they are not calendar events.\n\n"
+    "Rules:\n"
+    "  - project_id is REQUIRED for every create; confirm with the user if unknown\n"
+    "  - date is a Unix timestamp in milliseconds; convert human-readable dates\n"
+    "  - is_ai_suggested: 1 when proactively proposing a checkpoint, 0 otherwise\n"
+    "  - is_approved: 0 until the user explicitly confirms; then 1\n"
+    "  - For update_checkpoint, use -1 for integer fields you do not want to change\n"
+    "  - Listing without a project_id returns all checkpoints across projects\n"
+    "  - Always echo the title and formatted date in your confirmation."
+)
+
+
+@tool
+async def list_checkpoints(project_id: str = "") -> str:
+    """List checkpoints. Provide project_id to scope to a specific project."""
+    return json.dumps({
+        "action": "list",
+        "table": "checkpoints",
+        "filters": {"projectId": project_id or None},
+    })
+
+
+@tool
+async def create_checkpoint(
+    project_id: str,
+    title: str,
+    date: int,
+    is_ai_suggested: int = 0,
+    is_approved: int = 0,
+) -> str:
+    """Create a project checkpoint (milestone).
+    project_id: REQUIRED UUID of the parent project
+    title: descriptive name for the milestone
+    date: Unix timestamp in milliseconds
+    is_ai_suggested: 1 if proactively suggested, 0 if user-requested
+    is_approved: 0 until the user confirms
+    """
+    return json.dumps({
+        "action": "create_record",
+        "table": "checkpoints",
+        "data": {
+            "projectId": project_id,
+            "title": title,
+            "date": date,
+            "isAiSuggested": is_ai_suggested,
+            "isApproved": is_approved,
+        },
+    })
+
+
+@tool
+async def update_checkpoint(
+    checkpoint_id: str,
+    title: str = "",
+    date: int = -1,
+    is_approved: int = -1,
+) -> str:
+    """Update a checkpoint. Only pass fields that should change.
+    checkpoint_id: UUID of the checkpoint (required)
+    date: -1 means unchanged; any other value sets the new date (ms timestamp)
+    is_approved: -1 means unchanged; 0 or 1 sets the approval state
+    """
+    updates: dict[str, Any] = {}
+    if title:
+        updates["title"] = title
+    if date != -1:
+        updates["date"] = date
+    if is_approved != -1:
+        updates["isApproved"] = is_approved
+    return json.dumps({
+        "action": "update_record",
+        "table": "checkpoints",
+        "data": {"id": checkpoint_id, "updates": updates},
+    })
+
+
+@tool
+async def delete_checkpoint(checkpoint_id: str) -> str:
+    """Delete a checkpoint permanently by its UUID."""
+    return json.dumps({
+        "action": "delete_record",
+        "table": "checkpoints",
+        "data": {"id": checkpoint_id},
+    })
+
+
+@registry.register
+class CheckpointAgent(ChatAgent):
+    def get_name(self) -> str:
+        return "checkpoint_agent"
+
+    def get_description(self) -> str:
+        return "Manages project checkpoints (milestones): list, create, update, delete"
+
+    def get_tools(self) -> list[Any]:
+        return [list_checkpoints, create_checkpoint, update_checkpoint, delete_checkpoint]
+
+    async def handle(self, query: str, context: dict[str, Any]) -> str:
+        llm = ChatOpenAI(model="gpt-4o", temperature=0, api_key=settings.OPENAI_API_KEY)
+        messages = [
+            SystemMessage(content=_SYSTEM_PROMPT),
+            HumanMessage(
+                content=f"User query: {query}\nContext: {json.dumps(context)[:1000]}"
+            ),
+        ]
+        return await self._tool_loop(llm, messages, self.get_tools())