Adopt ConfigKit for pipeline loading

docs/internal/overview.md

@@ -37,7 +37,7 @@ failed stage or required manifest save prevents later stages from starting.
 | --- | --- | --- |
 | Executable | `cmd/narratio` | Process entry, standard stream wiring, argument handoff, and exit status. |
 | Application orchestration | `internal/app` | Command dispatch, configuration selection, secret-file environment loading, production composition, session locking, planning, execution, restore, and user-facing reporting. |
-| Configuration | [`internal/config`](configuration.md) | Presence-aware root/import/profile composition, canonical party and family expansion, strict YAML loading, defaults, normalization, session templating, and validation. |
+| Configuration | [`internal/config`](configuration.md) | ConfigKit-backed pipeline imports and profiles, canonical party and family expansion, strict YAML loading, defaults, normalization, session templating, and validation. |
 | Pipeline stages | `internal/stage` | Canonical stage registry, shared stage contract, execution dependencies, and implemented stage behavior. |
 | External boundaries | `internal/adapters`, `internal/audio` | WhisperX HTTP, downstream subprocesses, notification, object storage, and S3 audio materialization behind Narratio contracts. |
 | Manifests | `internal/manifest` | Durable session progress, stage transitions, validation, and atomic persistence. |
@@ -105,8 +105,8 @@ so any earlier replacement can stale a prior cleanup result.
 
 ## Focused Documentation
 
-- [Configuration Internals](configuration.md): pipeline composition, import
-  confinement, field ownership, decoding, and root-relative path semantics.
+- [Configuration Internals](configuration.md): pipeline imports and profiles,
+  field ownership, decoding, and root-relative path semantics.
 - [Adapter Internals](adapters.md): external adapter boundaries, composition,
   failure behavior, and test surfaces.
 - [Artifact Internals](artifacts.md): source identities, runtime catalog,