fix: pass SSH keys and config profile to startInstance in create form

The create-session-form was calling startInstance() without passing the
selected config profile and SSH keys. This caused the backend to receive
ssh_key_ids=[] and clear the keys that were stored during createInstance.
The .ssh directory was never mounted because instance.ssh_key_ids was
wiped during the start call.

Also includes minor formatting cleanup on the data migration.

Quality gates: pytest (18 passed)

apps/api/alembic/versions/2026_05_29_remove_ssh_keys_mount_from_manifest.py

@@ -25,14 +25,18 @@ def upgrade() -> None:
 
     # Get the pi-agent manifest
     result = conn.execute(
-        sa.text("SELECT id, manifest FROM tool_definition_manifests WHERE name = 'pi-agent'")
+        sa.text(
+            "SELECT id, manifest FROM tool_definition_manifests WHERE name = 'pi-agent'"
+        )
     )
     row = result.fetchone()
     if not row:
         return
 
     manifest_id, manifest_json = row
-    manifest = manifest_json if isinstance(manifest_json, dict) else json.loads(manifest_json)
+    manifest = (
+        manifest_json if isinstance(manifest_json, dict) else json.loads(manifest_json)
+    )
 
     mounts = manifest.get("mounts", [])
     original_count = len(mounts)
@@ -58,14 +62,18 @@ def downgrade() -> None:
     conn = op.get_bind()
 
     result = conn.execute(
-        sa.text("SELECT id, manifest FROM tool_definition_manifests WHERE name = 'pi-agent'")
+        sa.text(
+            "SELECT id, manifest FROM tool_definition_manifests WHERE name = 'pi-agent'"
+        )
     )
     row = result.fetchone()
     if not row:
         return
 
     manifest_id, manifest_json = row
-    manifest = manifest_json if isinstance(manifest_json, dict) else json.loads(manifest_json)
+    manifest = (
+        manifest_json if isinstance(manifest_json, dict) else json.loads(manifest_json)
+    )
 
     mounts = manifest.get("mounts", [])
 
@@ -74,14 +82,16 @@ def downgrade() -> None:
         return
 
     # Add the ssh_keys mount back
-    mounts.append({
-        "name": "ssh_keys",
-        "target": "/home/user/.ssh",
-        "source_type": "ssh_key",
-        "mode": "0700",
-        "file_mode": "0600",
-        "readonly": True,
-    })
+    mounts.append(
+        {
+            "name": "ssh_keys",
+            "target": "/home/user/.ssh",
+            "source_type": "ssh_key",
+            "mode": "0700",
+            "file_mode": "0600",
+            "readonly": True,
+        }
+    )
     manifest["mounts"] = mounts
 
     conn.execute(