Document read-only submodules policy

bible-local/architecture/system-overview.md

@@ -58,6 +58,8 @@ Fills gaps where Redfish/logpile is blind:
 - `bee` should populate current component state, hardware inventory, telemetry, and `status_checked_at`.
 - Historical status transitions and component replacement logic belong to the centralized ingest/lifecycle system, not to `bee`.
 - Contract fields that have no honest local source on a generic Linux host may remain empty.
+- Embedded submodules such as `internal/chart/` and `bible/` are read-only for `bee` feature work.
+- If the UI needs extra information, `bee` must emit it through the standard audit JSON contract rather than patching `chart`.
 
 ## Tech stack
 
@@ -101,7 +103,7 @@ Fills gaps where Redfish/logpile is blind:
 | `iso/builder/` | ISO build scripts and `live-build` profile |
 | `iso/overlay/` | Source overlay copied into a staged build overlay |
 | `iso/vendor/` | Optional pre-built vendor binaries (storcli64, sas2ircu, sas3ircu, arcconf, ssacli, …) |
-| `internal/chart/` | Git submodule with `reanimator/chart`, embedded into `bee web` |
+| `internal/chart/` | Git submodule with `reanimator/chart`, embedded into `bee web`; update by submodule pointer only, never by local `bee`-specific edits |
 | `iso/builder/VERSIONS` | Pinned versions: Debian, Go, NVIDIA driver, kernel ABI |
 | `iso/builder/smoketest.sh` | Post-boot smoke test — run via SSH to verify live ISO |
 | `iso/overlay/etc/profile.d/bee.sh` | tty1 welcome message with web UI URLs |