intermittent commit

docs/UI_UX_DECISION_LEDGER.md

@@ -38,6 +38,7 @@ contestability, responsibility, and traceability at the point of action.
 | UX-012 | Automated actions must remain inspectable. The UI must show the system actor, trigger, policy result, observed effects, and failure/manual-intervention state when automation changes administrative state. | Accepted | Workflow, automation, connectors, tasks, audit |
 | UX-013 | Contestable decisions must expose provenance. Denials, locks, generated outputs, calculated defaults, policy decisions, access decisions, and retention decisions need a reachable source path. | Accepted | Policy, access, templates, workflow, retention, records |
 | UX-014 | Retraction, expiry, undo, rollback, and delete controls must state the real limit of the operation. Corrective or future-only actions must not be described as if they undo already observed effects. | Accepted | Postbox, files, records, installer, workflow, payments |
+| UX-015 | Core owns the platform appearance contract. Modules must use shared CSS tokens and shared controls for theme-aware UI; they must not define independent light/dark palette systems. | Accepted | Core shell and all module WebUIs |
 
 ## Confirmed Implementation Decisions
 
@@ -138,6 +139,23 @@ adaptive form, not force a linear wizard.
 - Wizard shells remain available for assisted setup, first-run guidance,
   imports, discovery-heavy flows, and operational preflight workflows.
 
+### DUE-008: Platform Theme Contract
+
+Decision: the WebUI shell exposes a small, stable appearance contract based on
+shared CSS tokens and persisted user preference selection.
+
+- Core applies `system`, `light`, and `dark` preferences at the document root.
+- Core owns shared tokens such as `--bg`, `--bar`, `--panel`, `--surface`,
+  `--line`, `--line-dark`, `--text`, `--text-strong`, `--muted`, semantic
+  status colors, radii, shadows, and disabled-control colors.
+- Modules must style new UI with these tokens and shared controls. Module-local
+  CSS may tune layout and spacing, but it must not introduce a separate
+  appearance system.
+- Appearance controls live in user settings first. Tenant defaults and policy
+  enforcement can be added later without changing the token contract.
+- Visual preview in settings is illustrative; it must reflect token families,
+  not become a second theme implementation.
+
 ## Implementation Sequence
 
 | Phase | Scope | Output |