Add reusable tools and assistant bindings

- Introduce a new `Tool` model and `AssistantToolBinding` for managing reusable tools within the application.
- Implement CRUD operations for tools in the new `tools` route, allowing for the creation, retrieval, updating, and deletion of tools.
- Update the `Assistant` model to include a list of tool IDs, enabling assistants to utilize these tools.
- Enhance the backend routes to synchronize tool bindings with assistants, ensuring proper management of tool associations.
- Add frontend components for tool management, including a tool picker in the assistant configuration, improving user experience in tool selection.
- Create a mobile call page to facilitate video calls, integrating camera and microphone selection for enhanced communication capabilities.
- Update API definitions to include tool-related types and operations, ensuring consistency across the application.
- Add a migration script to create the necessary database tables for tools and bindings, supporting the new functionality.

backend/migrations/versions/20260710_0002_add_tools.py

@@ -0,0 +1,72 @@
+"""add reusable tools and assistant bindings
+
+Revision ID: 20260710_0002
+Revises: 20260709_0001
+Create Date: 2026-07-10 00:00:00.000000
+"""
+
+from collections.abc import Sequence
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+
+revision: str = "20260710_0002"
+down_revision: str | Sequence[str] | None = "20260709_0001"
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "tools",
+        sa.Column("id", sa.String(length=40), nullable=False),
+        sa.Column("name", sa.String(length=128), nullable=False),
+        sa.Column("function_name", sa.String(length=64), nullable=False),
+        sa.Column("type", sa.String(length=24), nullable=False),
+        sa.Column("description", sa.String(length=2048), server_default="", nullable=False),
+        sa.Column(
+            "definition",
+            postgresql.JSONB(astext_type=sa.Text()),
+            server_default=sa.text("'{}'::jsonb"),
+            nullable=False,
+        ),
+        sa.Column(
+            "secrets",
+            postgresql.JSONB(astext_type=sa.Text()),
+            server_default=sa.text("'{}'::jsonb"),
+            nullable=False,
+        ),
+        sa.Column("status", sa.String(length=16), server_default="active", nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.text("now()"), nullable=False),
+        sa.Column("updated_at", sa.DateTime(timezone=True), server_default=sa.text("now()"), nullable=False),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index("ix_tools_function_name", "tools", ["function_name"], unique=True)
+    op.create_index("ix_tools_type", "tools", ["type"])
+    op.create_index("ix_tools_status", "tools", ["status"])
+
+    op.create_table(
+        "assistant_tool_bindings",
+        sa.Column("assistant_id", sa.String(length=40), nullable=False),
+        sa.Column("tool_id", sa.String(length=40), nullable=False),
+        sa.Column("created_at", sa.DateTime(timezone=True), server_default=sa.text("now()"), nullable=False),
+        sa.ForeignKeyConstraint(["assistant_id"], ["assistants.id"], ondelete="CASCADE"),
+        sa.ForeignKeyConstraint(["tool_id"], ["tools.id"], ondelete="RESTRICT"),
+        sa.PrimaryKeyConstraint("assistant_id", "tool_id"),
+    )
+    op.create_index(
+        "ix_assistant_tool_bindings_tool_id",
+        "assistant_tool_bindings",
+        ["tool_id"],
+    )
+
+
+def downgrade() -> None:
+    op.drop_index("ix_assistant_tool_bindings_tool_id", table_name="assistant_tool_bindings")
+    op.drop_table("assistant_tool_bindings")
+    op.drop_index("ix_tools_status", table_name="tools")
+    op.drop_index("ix_tools_type", table_name="tools")
+    op.drop_index("ix_tools_function_name", table_name="tools")
+    op.drop_table("tools")