diff --git a/.github/actions/dapr4s-mill-plugin/action.yml b/.github/actions/dapr4s-mill-plugin/action.yml
index edb3082..32153ad 100644
--- a/.github/actions/dapr4s-mill-plugin/action.yml
+++ b/.github/actions/dapr4s-mill-plugin/action.yml
@@ -1,13 +1,35 @@
 name: dapr4s Mill plugin
 description: >-
   publishLocal the mill-dapr4s-wasm plugin that build.mill's header loads, from the dapr4s commit pinned in
-  wasm/dapr4s-wasm.env (cached per commit). Every job that runs ./mill needs it until the plugin is released.
+  wasm/dapr4s-wasm.env (cached per commit), and the unreleased mill-scalablytyped dapr4s's meta-build loads.
+  Every job that runs ./mill needs both until they are released.
 runs:
   using: composite
   steps:
     - name: Read the dapr4s pin (wasm/dapr4s-wasm.env)
       shell: bash
       run: grep -E '^[A-Z0-9_]+=' wasm/dapr4s-wasm.env >> "$GITHUB_ENV"
+    # dapr4s's meta-build loads an unreleased mill-scalablytyped: dapr4s's scripts/upstream-snapshot.sh (at the
+    # pinned commit) builds it from a pinned upstream commit and installs it locally. Cached by the script's hash.
+    # Mill itself is the released 1.3.1 (.mill-version).
+    - name: Fetch dapr4s's upstream-snapshot.sh
+      id: snapshot
+      shell: bash
+      run: |
+        f="$RUNNER_TEMP/upstream-snapshot.sh"
+        curl -fsSL --retry 3 -o "$f" \
+          "https://raw.githubusercontent.com/sideeffffect/dapr4s/$DAPR4S_COMMIT/scripts/upstream-snapshot.sh"
+        chmod +x "$f"
+        echo "script=$f" >> "$GITHUB_OUTPUT"
+        echo "hash=$(sha256sum "$f" | cut -c1-16)" >> "$GITHUB_OUTPUT"
+    - name: Cache the upstream mill-scalablytyped snapshot
+      uses: actions/cache@v5
+      with:
+        path: ~/.ivy2/local/com.github.lolgab
+        key: upstream-snapshot-${{ steps.snapshot.outputs.hash }}
+    - name: Build the upstream mill-scalablytyped snapshot
+      shell: bash
+      run: ${{ steps.snapshot.outputs.script }}
     - name: Cache the dapr4s Mill plugin (~/.ivy2/local)
       id: cache
       uses: actions/cache@v5
diff --git a/.github/workflows/e2e.yml b/.github/workflows/e2e.yml
index 6eb5028..80841be 100644
--- a/.github/workflows/e2e.yml
+++ b/.github/workflows/e2e.yml
@@ -3,13 +3,13 @@ name: E2E Tests
 on:
   push:
     branches: [main, master]
+  # Every pull request, also those stacked on another PR's branch.
   pull_request:
-    branches: [main, master]
 
 jobs:
   format:
     runs-on: ubuntu-latest
-    timeout-minutes: 15
+    timeout-minutes: 45
     steps:
       - uses: actions/checkout@v5
 
@@ -246,14 +246,14 @@ jobs:
   # Mill plugin mill-dapr4s-wasm. dapr4s itself comes from Maven Central (dapr4s_sjs1_3 3.0.0); the plugin and the
   # small dapr4s wasm artifacts (dapr4s-wasm, dapr4s-wasm-glue(-exports), dapr4s-wasm-scalalib-overlay,
   # dapr4s-wasm-linker) come from a publishLocal of the dapr4s commit PINNED in wasm/dapr4s-wasm.env (a commit of
-  # https://github.com/sideeffffect/dapr4s/pull/45). Once they are released, the pin becomes a release version and
+  # https://github.com/sideeffffect/dapr4s/pull/47). Once they are released, the pin becomes a release version and
   # the dapr4s publish step goes away.
   # The components are composed with dapr-wasm-components 0.7.5 (compose.sh at the v0.7.5 tag) and run
   # in `wasmtime serve` next to a real daprd (dapr CLI, slim) + Redis (Docker); the e2e asserts their
   # real output, including 04's unchanged JVM caller calling the Wasm greeting-service.
   e2e-wasm:
     runs-on: ubuntu-latest
-    timeout-minutes: 45
+    timeout-minutes: 90
     name: e2e (wasm components)
 
     steps:
@@ -319,7 +319,26 @@ jobs:
           dapr init --slim --runtime-version 1.17.7
           echo "$HOME/.dapr/bin" >> "$GITHUB_PATH"
 
-      # The plugin + the five dapr4s wasm artifacts (incl. dapr4s-wasm-linker, compiled from scala-wasm's release
+      # dapr4s's meta-build loads an unreleased mill-scalablytyped: dapr4s's scripts/upstream-snapshot.sh (at the
+      # pinned commit) builds and installs it, cached by its hash. Mill itself is the released 1.3.1.
+      - name: Fetch dapr4s's upstream-snapshot.sh
+        id: snapshot
+        run: |
+          f="$RUNNER_TEMP/upstream-snapshot.sh"
+          curl -fsSL --retry 3 -o "$f" \
+            "https://raw.githubusercontent.com/sideeffffect/dapr4s/$DAPR4S_COMMIT/scripts/upstream-snapshot.sh"
+          chmod +x "$f"
+          echo "script=$f" >> "$GITHUB_OUTPUT"
+          echo "hash=$(sha256sum "$f" | cut -c1-16)" >> "$GITHUB_OUTPUT"
+      - name: Cache the upstream mill-scalablytyped snapshot
+        uses: actions/cache@v5
+        with:
+          path: ~/.ivy2/local/com.github.lolgab
+          key: upstream-snapshot-${{ steps.snapshot.outputs.hash }}
+      - name: Build the upstream mill-scalablytyped snapshot
+        run: ${{ steps.snapshot.outputs.script }}
+
+      # The plugin + the five dapr4s wasm artifacts (incl. dapr4s-wasm-linker_2.13, compiled from scala-wasm's release
       # commit + dapr4s's patch) land in ~/.ivy2/local and are a pure function of the pinned dapr4s commit: cache
       # them under it. On a miss, wasm/scripts/publish-dapr4s-wasm.sh clones dapr4s at that commit and runs its
       # Mill publishLocal. It must run before the first ./mill here (build.mill's header loads the plugin).
@@ -347,7 +366,7 @@ jobs:
 
   slides:
     runs-on: ubuntu-latest
-    timeout-minutes: 20
+    timeout-minutes: 45
 
     steps:
       - uses: actions/checkout@v5
diff --git a/AGENTS.md b/AGENTS.md
index 7cb47fd..212020e 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -120,8 +120,11 @@ Source files live under `src/<package>/` within each module directory, e.g.:
 - **Dapr CLI** and runtime: https://docs.dapr.io/getting-started/install-dapr-cli/
 - **Redis** on `localhost:6379` — `docker run -d -p 6379:6379 redis:7`
 - **JVM ≥ 21** — `java -version`
-- **Mill 1.3.x** — use the `./mill` launcher (it reads `.mill-version`). Mill >= 1.3.0 is required
-  for the Scala.js JSPI switch (see "Scala.js examples").
+- **Mill 1.3.1** — use the `./mill` launcher (it reads `.mill-version`). It is the Mill the dapr4s
+  plugin is built against, and the first release with
+  [com-lihaoyi/mill#7783](https://github.com/com-lihaoyi/mill/pull/7783) (Scala.js organization +
+  `ModuleKind.WasmComponent`). Mill >= 1.3.0 is required for the Scala.js JSPI switch (see "Scala.js
+  examples").
 - **dapr4s published locally** (run once from the dapr4s repo):
   ```
   cd ../scala-safe-dapr
@@ -423,7 +426,7 @@ whole repository is one Mill build.
   directly) + `dapr4s-wasm` (the adapters), `dapr4s-wasm-glue(-exports)`, `dapr4s-wasm-scalalib-overlay`,
   `dapr4s-wasm-linker` and the plugin `mill-dapr4s-wasm`, which are **not released yet**: they come from a
   `publishLocal` of the dapr4s commit pinned in `wasm/dapr4s-wasm.env` (a commit of
-  [dapr4s PR #45](https://github.com/sideeffffect/dapr4s/pull/45)), at the version `build.mill`'s header pins.
+  [dapr4s PR #47](https://github.com/sideeffffect/dapr4s/pull/47)), at the version `build.mill`'s header pins.
   **Bootstrapping**: the header loads the plugin, so EVERY `./mill` command fails until it is in
   `~/.ivy2/local`. Run `wasm/scripts/publish-dapr4s-wasm.sh` (`plugin`, the default: only the plugin,
   needs git + Java) once after cloning; `all` also publishes the wasm artifacts `./mill wasm.e2e` needs
@@ -460,10 +463,10 @@ whole repository is one Mill build.
   [scala-wasm#268](https://github.com/scala-wasm/scala-wasm/pull/268)); the linker drops WIT aliases (WIT
   re-embed, [scala-wasm#269](https://github.com/scala-wasm/scala-wasm/pull/269)); the fork's and mainline's
   core libraries do not evict each other (exclusions, [scala-wasm#271](https://github.com/scala-wasm/scala-wasm/pull/271));
-  the nightly stdlib uses JS interop (`dapr4s-wasm-scalalib-overlay`); Mill has no Scala.js organization
-  setting / `ModuleKind.WasmComponent` ([mill#7783](https://github.com/com-lihaoyi/mill/pull/7783)) or
-  WIT-bindings task ([mill#7784](https://github.com/com-lihaoyi/mill/pull/7784)); no `main` in a reactor
-  (`ComponentRoot`).
+  the nightly stdlib uses JS interop (`dapr4s-wasm-scalalib-overlay`); Mill has no WIT-bindings task
+  ([mill#7784](https://github.com/com-lihaoyi/mill/pull/7784)); no `main` in a reactor (`ComponentRoot`).
+  (The Scala.js organization setting and `ModuleKind.WasmComponent`,
+  [mill#7783](https://github.com/com-lihaoyi/mill/pull/7783), are released in Mill 1.3.1 and used.)
 
 > The E2E (`Example14ObservabilityTest`) proves all three OpenTelemetry signals reach
 > SigNoz by asserting the funnel collector's own pipeline counters
diff --git a/README.md b/README.md
index 50360f8..3e55b17 100644
--- a/README.md
+++ b/README.md
@@ -107,7 +107,7 @@ published `dapr4s_sjs1_3` 3.0.0, whose Scala.js IR is linked into the component)
 (+ `-exports`; the Scala 2.13 WIT glue), `dapr4s-wasm-scalalib-overlay` and `dapr4s-wasm-linker`.
 
 **Prototype status.** The plugin and the artifacts are in
-[dapr4s PR #45](https://github.com/sideeffffect/dapr4s/pull/45) (not released yet), hence the
+[dapr4s PR #47](https://github.com/sideeffffect/dapr4s/pull/47) (not released yet), hence the
 `publishLocal` of the dapr4s commit pinned in `wasm/dapr4s-wasm.env` (at the version `build.mill`'s header
 pins). Because `build.mill`'s header loads the plugin, **every** `./mill` command needs it:
 `wasm/scripts/publish-dapr4s-wasm.sh` (default `plugin`: only the plugin, needs just git and Java) once
@@ -120,9 +120,10 @@ mainline Scala 3 (a small Scala 2.13 glue); the linker cannot pass WIT params th
 plugin re-embeds the WIT world, [scala-wasm#269](https://github.com/scala-wasm/scala-wasm/pull/269)); the
 fork's and mainline's core libraries do not evict each other (the exclusions,
 [scala-wasm#271](https://github.com/scala-wasm/scala-wasm/pull/271)); JS interop in the nightly's Scala.js
-stdlib (`dapr4s-wasm-scalalib-overlay`); Mill knows neither the fork's organization nor
-`ModuleKind.WasmComponent` ([mill#7783](https://github.com/com-lihaoyi/mill/pull/7783)) nor WIT bindings
-([mill#7784](https://github.com/com-lihaoyi/mill/pull/7784)).
+stdlib (`dapr4s-wasm-scalalib-overlay`); Mill has no WIT-bindings task
+([mill#7784](https://github.com/com-lihaoyi/mill/pull/7784)). (The fork's organization and
+`ModuleKind.WasmComponent`, [mill#7783](https://github.com/com-lihaoyi/mill/pull/7783), are released in Mill
+1.3.1 and used.)
 
 **Prerequisites**: JDK 25, Docker, the dapr CLI 1.15.1 + daprd 1.17.7 (`dapr init --slim`),
 [wasm-tools](https://github.com/bytecodealliance/wasm-tools) 1.261.0,
diff --git a/build.mill b/build.mill
index 5073afe..878ded6 100644
--- a/build.mill
+++ b/build.mill
@@ -1,4 +1,4 @@
-//| mvnDeps: ["com.github.sideeffffect::mill-dapr4s-wasm::3.0.0+35-0048d5b0-SNAPSHOT"]
+//| mvnDeps: ["com.github.sideeffffect::mill-dapr4s-wasm::3.0.0+44-1493515a-SNAPSHOT"]
 // The dapr4s Mill plugin for WASI components (examples 18/19, `object wasm` below). Pinned to a dapr4s commit
 // (wasm/dapr4s-wasm.env) until it is released: run wasm/scripts/publish-dapr4s-wasm.sh once before the first
 // `./mill` (it publishLocal's the plugin from that commit; `all` also the wasm artifacts the components need).
diff --git a/wasm/dapr4s-wasm.env b/wasm/dapr4s-wasm.env
index e90d114..ae162f3 100644
--- a/wasm/dapr4s-wasm.env
+++ b/wasm/dapr4s-wasm.env
@@ -1,6 +1,8 @@
 # The dapr4s commit the Mill plugin mill-dapr4s-wasm (build.mill's header) and the dapr4s wasm artifacts come from,
-# until they are released: a commit of dapr4s PR #45 (https://github.com/sideeffffect/dapr4s/pull/45, branch
-# build/mill). wasm/scripts/publish-dapr4s-wasm.sh publishLocal's them from it, at the version build.mill's header
+# until they are released: a commit of dapr4s PR #47 (https://github.com/sideeffffect/dapr4s/pull/47, branch
+# build/mill-upstream-snapshot: dapr4s on Mill 1.3.1 + the unreleased mill-scalablytyped that its
+# scripts/upstream-snapshot.sh installs; this repository's .mill-version uses the same Mill).
+# wasm/scripts/publish-dapr4s-wasm.sh publishLocal's them from it, at the version build.mill's header
 # pins (dapr4s derives it from git: <last tag>+<commits since>-<sha8>-SNAPSHOT), so the classpath is "Central dapr4s
 # + the local wasm artifacts":
 #   - dapr4s itself: com.github.sideeffffect::dapr4s_sjs1_3:$DAPR4S_CORE_RELEASE from Maven Central (Scala.js IR,
@@ -9,5 +11,5 @@
 #     glue), dapr4s-wasm-scalalib-overlay and dapr4s-wasm-linker.
 # Once released, this file goes away: the header pins a Maven Central release and CI stops building dapr4s.
 # Read by wasm/scripts/publish-dapr4s-wasm.sh and CI (.github/workflows/e2e.yml, .github/actions/dapr4s-mill-plugin).
-DAPR4S_COMMIT=0048d5b0a880e74ea409af7a555c99749efe07b3
+DAPR4S_COMMIT=1493515a8e86918129b7625e9c1bc4fff44e1423
 DAPR4S_CORE_RELEASE=3.0.0
diff --git a/wasm/scripts/publish-dapr4s-wasm.sh b/wasm/scripts/publish-dapr4s-wasm.sh
index faa8515..ae0f9d5 100755
--- a/wasm/scripts/publish-dapr4s-wasm.sh
+++ b/wasm/scripts/publish-dapr4s-wasm.sh
@@ -33,9 +33,9 @@ artifacts=(mill-dapr4s-wasm_mill1_3)
 case "$what" in
 plugin) ;;
 all)
-  modules+=('wasm.lib[release].wall' wasm.glue wasm.glueExports wasm.scalalibOverlay wasm.linker)
+  modules+=('wasm.lib[release].wall' wasm.glue wasm.glueExports wasm.scalalibOverlay 'wasm.linker[2.13.18]')
   artifacts+=(dapr4s-wasm_sjs1_3 dapr4s-wasm-glue_sjs1_2.13 dapr4s-wasm-glue-exports_sjs1_2.13
-    dapr4s-wasm-scalalib-overlay dapr4s-wasm-linker_2.12)
+    dapr4s-wasm-scalalib-overlay dapr4s-wasm-linker_2.13)
   ;;
 *)
   echo "usage: $0 [plugin|all]" >&2
@@ -58,6 +58,8 @@ if [[ ! -d "$dir/.git" ]]; then
 fi
 git -C "$dir" fetch --quiet --tags origin "$DAPR4S_COMMIT" 2>/dev/null || git -C "$dir" fetch --quiet --tags origin
 git -C "$dir" checkout --quiet --force "$DAPR4S_COMMIT"
+# dapr4s builds with an unreleased mill-scalablytyped: install it first (idempotent).
+"$dir/scripts/upstream-snapshot.sh"
 args=()
 for m in "${modules[@]}"; do
   [[ ${#args[@]} -gt 0 ]] && args+=(+)