feat: consolidate shared UI and harden browser authority for release

docs/DEPLOYMENT_OPERATOR_GUIDE.md

@@ -74,6 +74,19 @@ Operator rule: take a database backup before applying migrations or destructive
 module retirement. For non-SQLite databases, configure deployment-specific
 backup/restore hooks for the module installer.
 
+#### Ownership-history upgrade repair
+
+Core revision `c58a2d7e9f10` repairs existing ownership-transfer tables that
+predate the `decisions` column. Such installations can otherwise return HTTP
+500 from `/api/v1/ownership/transfers`, including Campaign Settings. Apply the
+normal forward migrations after taking a backup; do not stamp a revision or
+recreate the table. The repair is available on both migration tracks, adds only
+the missing non-null JSON column, and initializes old rows with an empty list.
+It preserves owners, approvals, transfer states, revisions, timestamps, and any
+existing decision history. Historical decisions are not reconstructed or
+invented. Downgrading this repair retains the additive column and its evidence.
+Verify that ownership-transfer listing and Campaign Settings load after upgrade.
+
 ### PostgreSQL Production Target
 
 PostgreSQL is the primary development and production target. SQLite remains
@@ -408,6 +421,27 @@ To stop PostgreSQL and Redis when the launcher exits:
 GOVOPLAN_STOP_PROFILE_DEPENDENCIES_ON_EXIT=1 tools/launch/launch-production-like-dev.sh
 ```
 
+## Development WebUI Dependency Caches
+
+The application and browser-conformance harness share installed JavaScript
+packages but must not share Vite's optimized-dependency cache. The application
+uses `webui/node_modules/.vite/govoplan-app`; the conformance harness uses
+`webui/node_modules/.vite/govoplan-conformance`. Keep these explicit sibling
+directories when adding development or test configurations. Setting a different
+Vite `root` alone does not isolate this cache.
+
+A shared cache can make otherwise healthy Workflow, Dataflow or deferred editors
+show “The resource could not be loaded.” The browser then reports an asset such
+as `@xyflow_react.js` with HTTP 504 `Outdated Optimize Dep`, while the corresponding
+API still returns HTTP 200. This is not a missing workflow permission or a reason
+to rerun a pipeline. Preserve unsaved work, let the existing development server
+reload the corrected configuration (or restart that WebUI server), then reload
+the browser. Do not clear application data, change grants or restart delivery
+workers to repair a frontend dependency cache.
+
+Run `npm run test:vite-cache-isolation` in `govoplan-core/webui` to verify the real
+resolved Vite configurations without starting servers or overwriting caches.
+
 ## Module Install/Uninstall Operations
 
 Use Admin > System > Modules for planning. The running API server validates and