feat: deep-agent canvas, live observability, and multi-environment tooling

Self-hosted platform for building, testing, and shipping LangChain/LangGraph agents. Deep-agent sub-agents on the canvas, a live tracing/observability timeline, auto-provisioned built-in tools with import/export, per-environment tool variables, streamed evaluations, and per-user auth token forwarding.

apps/api/migrations/env.py

@@ -0,0 +1,49 @@
+"""Alembic environment for Forge.
+
+Uses the app's `Base.metadata` as the autogenerate target and the configured
+`FORGE_DATABASE_URL` (async drivers downgraded to their sync equivalent for the
+migration connection). Future schema changes: `alembic revision --autogenerate -m '…'`.
+"""
+
+from __future__ import annotations
+
+from alembic import context
+from sqlalchemy import create_engine, pool
+
+import forge.models  # noqa: F401 - register all tables on Base.metadata
+from forge.config import settings
+from forge.db.base import Base
+
+config = context.config
+target_metadata = Base.metadata
+
+
+def _sync_url() -> str:
+    # Alembic runs on a synchronous engine, so swap async drivers for an installed sync one:
+    # the stdlib driver for SQLite, and psycopg v3 for Postgres (the `postgres` extra ships
+    # psycopg[binary], not psycopg2). psycopg v3 is addressed as `postgresql+psycopg` and runs
+    # synchronously here. Idempotent if the URL already uses a sync driver.
+    url = settings.database_url
+    return url.replace("+aiosqlite", "").replace("+asyncpg", "+psycopg")
+
+
+def run_migrations_offline() -> None:
+    context.configure(url=_sync_url(), target_metadata=target_metadata, literal_binds=True,
+                      dialect_opts={"paramstyle": "named"})
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def run_migrations_online() -> None:
+    engine = create_engine(_sync_url(), poolclass=pool.NullPool)
+    with engine.connect() as connection:
+        context.configure(connection=connection, target_metadata=target_metadata)
+        with context.begin_transaction():
+            context.run_migrations()
+    engine.dispose()
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()