chore: harden common storage bootstrap and slim embedded db assets

Unify embedding config, build providers from system settings, and fail
startup when index builds error or time out. Move Surreal assets under
common/db so embeds exclude crate source, and read storage via streams.

main/Cargo.toml

@@ -30,6 +30,7 @@ retrieval-pipeline = { path = "../retrieval-pipeline" }
 [dev-dependencies]
 tower = "0.5"
 uuid = { workspace = true }
+chrono = { workspace = true }
 common = { path = "../common", features = ["test-utils"] }
 
 [[bin]]