fix(immutable): remove Immutable (option 2)

.changeset/remove-immutable.md

@@ -0,0 +1,47 @@
+---
+'@talend/react-cmf': major
+'@talend/react-containers': major
+'@talend/react-cmf-cqrs': major
+'@talend/react-components': major
+'@talend/react-sagas': major
+'@talend/react-stepper': patch
+'@talend/react-flow-designer': major
+---
+
+feat: remove immutable dependency
+
+## Breaking changes
+
+### `@talend/react-cmf` (major)
+
+The CMF Redux store no longer uses ImmutableJS. `state.cmf.collections` and `state.cmf.components` are now plain objects.
+
+Migrate:
+- `.get(key)` → `[key]`
+- `.getIn([a, b])` → `lodash.get(state, [a, b])`
+- `.toJS()` → identity (already plain JS)
+- `.size` → `Object.keys(x).length`
+
+The `cmf.selectors.collections.*` and `cmf.selectors.components.*` APIs still work and are the recommended way to access CMF state.
+
+### `@talend/react-containers` (major)
+
+`defaultState` is now a plain object. Selectors updated accordingly. Same migration as above.
+
+### `@talend/react-cmf-cqrs` (major)
+
+`state.ack` is now a plain object. Consumers reading ack state directly must migrate `.get(key)` → `[key]`.
+
+### `@talend/react-sagas` (major)
+
+Exported functions `findPenders(state)` and `findPenderById(state, id)` now return plain JS values instead of Immutable structures. Any consumer calling `.get()`, `.set()`, `.toJS()`, or `.size` on the return values must migrate to plain object access.
+
+### `@talend/react-components` (major)
+
+The `Iterable.isIterable` backward-compat guard was removed from `ActionDropdown`. Consumers passing an Immutable List as `items` will no longer work — migrate to plain arrays.
+
+`immutable` and `react-immutable-proptypes` removed from published `dependencies`.
+
+### `@talend/react-flow-designer` (major)
+
+`immutable` removed from `peerDependencies`. Consumers must no longer install `immutable` as a peer dependency.