kibertoad · kibertoad · Jul 19, 2026 · Jul 19, 2026
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -15,7 +15,15 @@ Implements the counter-proposal from the cat-factory slice-4 triage (`docs/subje
 - **`@modular-vue/vue`** (re-exported from `@modular-vue/core`) — the same surface as a `computed`-based composable plus `<PanelsOutlet>` with `#empty` / `#wrap` slots and `provide`-based `usePanelSubject`. `usePanels` accepts `MaybeRefOrGetter` for the group, subject, and `onDuplicate`, and tracks **both** runtime slot sources — the reactive computed and the `recalculateSlots()` signal `Ref` — serving whichever produced the more recent evaluation, so dynamic-slot panels update on either path (matching the React host's behavior).
 - **`ModuleErrorBoundary`** (both bindings) — new optional `label` prop (default `"Module"`) naming the failing unit in the notice and console message; `<PanelsOutlet>` passes `"Panel"` so a crashed panel isn't mislabeled a module.
 - **Docs** — new [`docs/subject-panels.md`](docs/subject-panels.md) guide (entry shape, resolver semantics, both hosts, the Vue reactivity caveat, `when` vs `dynamicSlots`, `subjectKey`, panels-vs-pairing); the compositions README's sibling-primitive comparison extended three → four; cross-links from `reactive-slots-vue.md` and `remote-capability-manifests.md`; the triage doc gains its Resolution section.
-- **Housekeeping (Gap D)** — the Vue family peer ranges (`vue`, `vue-core`, `vue-runtime`, `vue-nuxt`, `vue-journeys`, `vue-compositions`, `vue-testing`) widen to admit `@modular-frontend/core@^0.3.0`, aligning lagging `^0.1.0`-only ranges with the engine version already in the workspace.
+- **Housekeeping (Gap D)** — the `@modular-frontend/core` peer ranges are widened and unified so adopting panels (which lives in `@modular-frontend/core@0.4.0`) no longer collides with bindings that were still pinned to older lines. See the dedicated entry below.
+
+### Changed — `@modular-frontend/core` as a shared peer dependency (panels adoption)
+
+Adopting panels was harder than it should have been: panels ship in `@modular-frontend/core@0.4.0`, but much of the ecosystem still constrained the engine to older lines, so an install that pulled `0.4.0` for panels tripped peer-dependency conflicts against packages that only admitted `^0.3.0` (or, worse, `^0.1.0`). The fix treats `@modular-frontend/core` as what it is — the one framework-neutral singleton the whole tree shares — and expresses that with peer dependencies rather than hand-maintained per-minor ranges.
+
+- **Unified, forward-looking peer range** — every binding that peer-depends on `@modular-frontend/core` now declares a single `>=0.1.0 <2.0.0` range instead of an enumerated `^0.1.0 || ^0.2.0 || ^0.3.0` (or a lone `^0.1.0`). Under semver a `0.x` caret is patch-only, so the old union was really `>=0.1.0 <0.4.0` — it excluded `0.4.0` and every future minor, and each release required a manual append (the step that was missed for `0.4.0`). The open range admits the whole pre-`2.0` line in one expression, so future additive `0.x`/`1.x` engine releases need no per-package edit. Touches `@modular-vue/vue`, `@modular-vue/core`, `@modular-vue/runtime`, `@modular-vue/nuxt`, `@modular-vue/journeys`, `@modular-vue/compositions`, `@modular-vue/testing`, `@modular-angular/angular`, `@modular-angular/core`, and `@modular-frontend/testing` (the last three were still on `^0.1.0`, excluding `0.2`/`0.3` as well).
+- **Hard dependencies promoted to peers** — `@modular-react/core`, `@modular-frontend/compositions-engine`, and `@modular-frontend/journeys-engine` carried `@modular-frontend/core` as a plain `dependencies: "workspace:*"`, which publishes as an exact version pin and can install a _second_ engine copy alongside a consumer's own. Because the engine holds identity-sensitive runtime (the slots context, module/registry identity, the shared resolver reductions behind panels and compositions), a duplicate copy silently breaks identity checks and gives structurally-but-not-nominally compatible types. These now declare `@modular-frontend/core` as a `peerDependencies` (`>=0.1.0 <2.0.0`) backed by a `devDependencies: "workspace:*"`, matching the stance `@modular-frontend/testing` already took and the packaging philosophy documented in `scripts/check-publish.mjs` (shared singletons stay peers so a consumer's types bind to their single copy). Verified end-to-end by `check:publish` (publint + attw on the packed tarballs).
+- **Vue scaffolder** — `@modular-vue/cli` baked `@modular-frontend/core: "^0.1.0"` into every generated app, so a freshly scaffolded project was born unable to install panels. It now bakes the same `>=0.1.0 <2.0.0` range.
 
 ### Changed — downstream feedback: types, plugins, and the cancel affordance
 

diff --git a/packages/angular-router-core/package.json b/packages/angular-router-core/package.json
@@ -45,6 +45,6 @@
     "@angular/core": "^20.0.0 || ^21.0.0 || ^22.0.0",
     "@angular/router": "^20.0.0 || ^21.0.0 || ^22.0.0",
     "@modular-angular/angular": "^0.1.0",
-    "@modular-frontend/core": "^0.1.0"
+    "@modular-frontend/core": ">=0.1.0 <2.0.0"
   }
 }
diff --git a/packages/angular/package.json b/packages/angular/package.json
@@ -45,6 +45,6 @@
   },
   "peerDependencies": {
     "@angular/core": "^20.0.0 || ^21.0.0 || ^22.0.0",
-    "@modular-frontend/core": "^0.1.0"
+    "@modular-frontend/core": ">=0.1.0 <2.0.0"
   }
 }
diff --git a/packages/compositions-engine/package.json b/packages/compositions-engine/package.json
@@ -29,16 +29,17 @@
     "prepublishOnly": "pnpm build",
     "typecheck": "tsc --noEmit"
   },
-  "dependencies": {
-    "@modular-frontend/core": "workspace:*"
-  },
   "devDependencies": {
+    "@modular-frontend/core": "workspace:*",
     "happy-dom": "^20.9.0",
     "oxfmt": "^0.51.0",
     "oxlint": "^1.66.0",
     "rolldown-plugin-dts": "^0.26.0",
     "typescript": "^6.0.3",
     "vite": "^8.1.3",
     "vitest": "^4.1.10"
+  },
+  "peerDependencies": {
+    "@modular-frontend/core": ">=0.1.0 <2.0.0"
   }
 }
diff --git a/packages/core/package.json b/packages/core/package.json
@@ -29,15 +29,16 @@
     "prepublishOnly": "pnpm build",
     "typecheck": "tsc --noEmit"
   },
-  "dependencies": {
-    "@modular-frontend/core": "workspace:*"
-  },
   "devDependencies": {
+    "@modular-frontend/core": "workspace:*",
     "oxfmt": "^0.51.0",
     "oxlint": "^1.66.0",
     "rolldown-plugin-dts": "^0.26.0",
     "typescript": "^6.0.3",
     "vite": "^8.1.3",
     "vitest": "^4.1.10"
+  },
+  "peerDependencies": {
+    "@modular-frontend/core": ">=0.1.0 <2.0.0"
   }
 }
diff --git a/packages/frontend-testing/package.json b/packages/frontend-testing/package.json
@@ -39,6 +39,6 @@
     "vitest": "^4.1.10"
   },
   "peerDependencies": {
-    "@modular-frontend/core": "^0.1.0"
+    "@modular-frontend/core": ">=0.1.0 <2.0.0"
   }
 }
diff --git a/packages/journeys-engine/package.json b/packages/journeys-engine/package.json
@@ -33,16 +33,17 @@
     "prepublishOnly": "pnpm build",
     "typecheck": "tsc --noEmit"
   },
-  "dependencies": {
-    "@modular-frontend/core": "workspace:*"
-  },
   "devDependencies": {
+    "@modular-frontend/core": "workspace:*",
     "happy-dom": "^20.9.0",
     "oxfmt": "^0.51.0",
     "oxlint": "^1.66.0",
     "rolldown-plugin-dts": "^0.26.0",
     "typescript": "^6.0.3",
     "vite": "^8.1.3",
     "vitest": "^4.1.10"
+  },
+  "peerDependencies": {
+    "@modular-frontend/core": ">=0.1.0 <2.0.0"
   }
 }
diff --git a/packages/vue-cli/src/templates/scaffold.ts b/packages/vue-cli/src/templates/scaffold.ts
@@ -22,8 +22,8 @@ export const MODULAR_VUE_VERSION = "^1.0.0";
 const V = {
   /** `@modular-vue/*` family (core, runtime, vue, testing, journeys). */
   modularVue: MODULAR_VUE_VERSION,
-  /** `@modular-frontend/*` shared engine/core (0.x — tight range, see D-policy). */
-  modularFrontend: "^0.1.0",
+  /** `@modular-frontend/*` shared engine/core — one open range across the pre-2.0 line so a generated app is never pinned off the latest (e.g. panels landed in 0.4). */
+  modularFrontend: ">=0.1.0 <2.0.0",
   vue: "^3.5.0",
   vueRouter: "^5.0.0",
   vueTsc: "^3.3.0",

diff --git a/packages/vue-cli/test/__snapshots__/cli.test.ts.snap b/packages/vue-cli/test/__snapshots__/cli.test.ts.snap
@@ -23,7 +23,7 @@ dist/
     "typecheck": "vue-tsc --noEmit"
   },
   "dependencies": {
-    "@modular-frontend/core": "^0.1.0",
+    "@modular-frontend/core": ">=0.1.0 <2.0.0",
     "@modular-vue/vue": "^1.0.0",
     "wretch": "^2.11.0"
   },
@@ -286,7 +286,7 @@ export type CustomerOnboardingHandle = typeof customerOnboardingHandle
     "typecheck": "vue-tsc --noEmit"
   },
   "dependencies": {
-    "@modular-frontend/core": "^0.1.0",
+    "@modular-frontend/core": ">=0.1.0 <2.0.0",
     "@modular-vue/core": "^1.0.0",
     "@acme/app-shared": "workspace:*"
   },
@@ -485,7 +485,7 @@ const user = useStore('auth', (s) => s.user)
     "typecheck": "vue-tsc --noEmit"
   },
   "dependencies": {
-    "@modular-frontend/core": "^0.1.0",
+    "@modular-frontend/core": ">=0.1.0 <2.0.0",
     "@modular-vue/core": "^1.0.0",
     "@acme/app-shared": "workspace:*"
   },
@@ -733,7 +733,7 @@ onlyBuiltDependencies:
     "@acme/customer-onboarding-journey": "workspace:*",
     "@acme/dashboard-module": "workspace:*",
     "@acme/orders-module": "workspace:*",
-    "@modular-frontend/core": "^0.1.0",
+    "@modular-frontend/core": ">=0.1.0 <2.0.0",
     "@modular-vue/core": "^1.0.0",
     "@modular-vue/journeys": "^1.0.0",
     "@modular-vue/runtime": "^1.0.0",

diff --git a/packages/vue-compositions/package.json b/packages/vue-compositions/package.json
@@ -46,7 +46,7 @@
     "vue": "^3.5.40"
   },
   "peerDependencies": {
-    "@modular-frontend/core": "^0.1.0 || ^0.2.0 || ^0.3.0",
+    "@modular-frontend/core": ">=0.1.0 <2.0.0",
     "@modular-vue/vue": "^1.0.0",
     "vue": "^3.5.40"
   }

diff --git a/packages/vue-core/package.json b/packages/vue-core/package.json
@@ -42,7 +42,7 @@
     "vue-router": "^5.0.0"
   },
   "peerDependencies": {
-    "@modular-frontend/core": "^0.1.0 || ^0.2.0 || ^0.3.0",
+    "@modular-frontend/core": ">=0.1.0 <2.0.0",
     "@modular-vue/vue": "^1.0.0",
     "vue": "^3.5.40",
     "vue-router": "^5.0.0"

diff --git a/packages/vue-journeys/package.json b/packages/vue-journeys/package.json
@@ -51,7 +51,7 @@
     "vue": "^3.5.40"
   },
   "peerDependencies": {
-    "@modular-frontend/core": "^0.1.0 || ^0.2.0 || ^0.3.0",
+    "@modular-frontend/core": ">=0.1.0 <2.0.0",
     "@modular-vue/vue": "^1.0.0",
     "vue": "^3.5.40"
   }

diff --git a/packages/vue-nuxt/package.json b/packages/vue-nuxt/package.json
@@ -54,7 +54,7 @@
     "vue-router": "^5.0.0"
   },
   "peerDependencies": {
-    "@modular-frontend/core": "^0.1.0 || ^0.2.0 || ^0.3.0",
+    "@modular-frontend/core": ">=0.1.0 <2.0.0",
     "@modular-vue/runtime": "^1.0.0",
     "nuxt": "^4.4.0",
     "vue": "^3.5.40",

diff --git a/packages/vue-runtime/package.json b/packages/vue-runtime/package.json
@@ -47,7 +47,7 @@
     "vue-router": "^5.0.0"
   },
   "peerDependencies": {
-    "@modular-frontend/core": "^0.1.0 || ^0.2.0 || ^0.3.0",
+    "@modular-frontend/core": ">=0.1.0 <2.0.0",
     "@modular-vue/core": "^1.0.0",
     "@modular-vue/vue": "^1.0.0",
     "vue": "^3.5.40",

diff --git a/packages/vue-testing/package.json b/packages/vue-testing/package.json
@@ -48,7 +48,7 @@
     "vue-router": "^5.0.0"
   },
   "peerDependencies": {
-    "@modular-frontend/core": "^0.1.0 || ^0.2.0 || ^0.3.0",
+    "@modular-frontend/core": ">=0.1.0 <2.0.0",
     "@modular-frontend/testing": "^0.1.0",
     "@modular-vue/core": "^1.0.0",
     "@modular-vue/journeys": "^1.0.0",

diff --git a/packages/vue/package.json b/packages/vue/package.json
@@ -43,7 +43,7 @@
     "vue": "^3.5.40"
   },
   "peerDependencies": {
-    "@modular-frontend/core": "^0.1.0 || ^0.2.0 || ^0.3.0",
+    "@modular-frontend/core": ">=0.1.0 <2.0.0",
     "vue": "^3.5.40"
   }
 }