diff --git a/.claude/rules/ci.md b/.claude/rules/ci.md
index 7afaaebb5c..d1e31cd255 100644
--- a/.claude/rules/ci.md
+++ b/.claude/rules/ci.md
@@ -32,7 +32,9 @@ The required check names are in `AGENTS.md` (CI). Reading a red check: `.claude/
 
 ## Runners and toolchain
 
-- Every Xcode job in the test and release workflows runs on the `xcode-27` runner label, a GitHub preview image. actionlint learns the label from `.github/actionlint.yaml`.
+- Every Xcode job in the test and release workflows runs on the `xcode-27` runner label, a GitHub preview image, except Release Build. actionlint learns the label from `.github/actionlint.yaml`.
+- Release Build runs on `mac-mini-m4pro`, a repo-level self-hosted runner with the labels `self-hosted`, `macOS`, `ARM64` and `tablepro-release`: the maintainer's M4 Pro (12 cores, 24 GB, Xcode 27.1 at `/Applications/Xcode.app`), run by launchd as the maintainer's user.
+- No other workflow names `tablepro-release`. Release Build never takes a PR, and fork PR workflows need approval for every outside contributor.
 - The Xcode version and Apple's released build of it are written once, in `.github/actions/setup-xcode/action.yml`. It takes the one non-symlink `/Applications/Xcode*.app` whose `version.plist` has that version, fails on none or several, exports `DEVELOPER_DIR` to the job's later steps and prints `xcodebuild -version`.
 - A workflow never selects Xcode another way, and never runs an Xcode tool under `sudo`, which drops `DEVELOPER_DIR`. A test host gets it from the Unit plan (`.claude/rules/tests.md`, Plans).
 - A stable tag builds only on Apple's released Xcode: `setup-xcode` with `require-release` needs the pinned build and `licenseType` `GM` in the bundle's `LicenseInfo.plist`. The folder name is no signal: the image names the released 27A9275 `Xcode_27.1_Release_Candidate.app`.
@@ -63,8 +65,10 @@ The required check names are in `AGENTS.md` (CI). Reading a red check: `.claude/
 
 ## Release Build (`release-build.yml`)
 
-- Push to main or `release/**`, and dispatch; never a PR. Never cancelled. Not a required check.
-- `Changes (Release)` outputs `run` (detector `release`). `Release Build` runs on `xcode-27` with a 150-minute limit, with VERSION 0.0.0-dev and BUILD 9999999, so build.sh passes the version settings a tag passes.
+- Nightly at 19:00 UTC on main, push to `release/**`, and dispatch; never a PR. Never cancelled. Not a required check.
+- `Changes (Release)` outputs `run`. A dispatch always builds. A nightly runs the `release` detector against the head of the last nightly that ended green, read with `gh api`, so a quiet day builds nothing. A `release/**` push diffs `github.event.before`, and builds when the push created the branch.
+- `Release Build` runs on the self-hosted Mac; a dispatch with `runner: github` runs it on `xcode-27`. It has a 150-minute limit and VERSION 0.0.0-dev and BUILD 9999999, so build.sh passes the version settings a tag passes.
+- While the Mac is offline a run waits for it, and GitHub cancels a job still queued after 24 hours. The tag gate refuses a commit with any red run, so re-run that run once the Mac is back; a `runner: github` dispatch on the same commit does not replace it.
 - Setup as macOS Tests up to the SPM restore, which it never saves; then Go, `build-dameng.sh both` and `build-hana.sh both`.
 - `scripts/release/build.sh app --unsigned` archives the `TablePro` scheme; `build.sh plugins --unsigned` builds `RegistryPlugins` and copies the publish set, the targets `scripts/release/registry.py targets` reads from `.github/plugin-registry.json`, to `build/release/plugins`. Both build universal. They run `lipo -verify_arch` once per arch (arm64, x86_64), since Xcode 27's `lipo` takes one arch per call, then `verify-plugin-loads.sh`.
 - `scripts/release/package.sh app --unsigned` writes the release assets: the DMG, the `.tar.xz` (extracted and compared with the app) and the dSYMs zip; `package.sh plugins` writes one zip per plugin and the plugin dSYMs zip.
@@ -129,7 +133,7 @@ The required check names are in `AGENTS.md` (CI). Reading a red check: `.claude/
 ## What runs where
 
 - A pull request: both changes jobs; macOS Tests and iOS and Package Tests unless their detector says false (Oracle only when its detector is not false); SwiftLint; Repo Hygiene; PR title. `AllPlugins` only when the `plugins` detector is not false.
-- A push to main or `release/**`: the same minus PR title, plus Release Build; never cancelled, the SPM cache saved on a miss. Every code push runs both plans in full; a docs-only or changelog-only push skips the suites through the detector.
+- A push to main or `release/**`: the same minus PR title; never cancelled, the SPM cache saved on a miss. Every code push runs both plans in full; a docs-only or changelog-only push skips the suites through the detector. A `release/**` push also runs Release Build; main gets it nightly.
 - A `v*` tag runs only `release.yml`, and a `linux-v*` tag only `release-linux.yml`, which calls `linux-packages.yml`. The test workflows never run on a tag.
 - `workflow_dispatch` exists on every workflow except `pr-title.yml` and `release.yml`.
 - `build-linux.yml` builds and tests the Linux app (`linux/docs/testing.md`, CI). Its `Changes (Linux)` job skips the rest when nothing under `linux/` or the scripts and workflows it reads changed, and its `Linux` job gates on all of them.
@@ -140,7 +144,7 @@ The required check names are in `AGENTS.md` (CI). Reading a red check: `.claude/
 - `release.yml` restores that cache and never saves it, since a save in tag scope is unreadable from other refs.
 - `release-build.yml` restores it and leaves the save to macOS Tests.
 - There is no other Apple cache: no libs or DerivedData cache, and none in the iOS or plugin workflows. The Linux jobs cache Cargo builds through `Swatinem/rust-cache` and the Flatpak build.
-- CI fits the GitHub Free and Pro plans: no paid larger runner, no self-hosted Mac. At most 5 macOS jobs run at once, and main runs queue behind PR runs for those slots.
+- CI fits the GitHub Free and Pro plans: no paid larger runner. At most 5 hosted macOS jobs run at once, and main runs queue behind PR runs for those slots. Release Build takes none of them unless a dispatch picks `runner: github`.
 
 ## Writing workflow and lint code
 
diff --git a/.claude/skills/release/SKILL.md b/.claude/skills/release/SKILL.md
index 889c6b5f5a..100cead085 100644
--- a/.claude/skills/release/SKILL.md
+++ b/.claude/skills/release/SKILL.md
@@ -28,7 +28,8 @@ Before any decision, gather:
 - open regressions: `gh issue list --label regression --state open`;
 - the newest beta's age, `gh release view v<X.Y>.0-beta.<N> --json publishedAt -q .publishedAt`, and the code on the line after it, `git log --oneline v<X.Y>.0-beta.<N>..origin/release/<X.Y> -- . ':!changelog.d' ':!CHANGELOG.md'`;
 - open Dependabot alerts: `gh api --paginate 'repos/TableProApp/TablePro/dependabot/alerts?state=open&per_page=100' -q '.[].security_advisory.summary'`;
-- main's push runs: `gh run list --branch main --event push --limit 10`, with macOS Tests, iOS and Package Tests and Release Build green on the commit you would cut;
+- main's push runs: `gh run list --branch main --event push --limit 10`, with macOS Tests and iOS and Package Tests green on the commit you would cut;
+- main's Release Builds: `gh run list --workflow release-build.yml --branch main --status success --limit 5`. The commit you would cut needs one, nightly or dispatched (`gh workflow run release-build.yml --ref main`);
 - whether `main` has the last stable's `## [X.Y.Z]` heading. If not, the forward-port is missing and the next tag will refuse to build: do that first (section 9).
 
 ## 3. Decide what ships
diff --git a/.github/workflows/release-build.yml b/.github/workflows/release-build.yml
index 5305f51ea0..c9b5cf0450 100644
--- a/.github/workflows/release-build.yml
+++ b/.github/workflows/release-build.yml
@@ -1,12 +1,21 @@
 name: Release Build
 
 # The Release configuration of the app and every registry plugin, universal and unsigned, packaged
-# the way a tag packages it, so a packaging failure shows on the commit instead of on the tag.
+# the way a tag packages it, so a packaging failure shows before the tag: nightly on main, on every
+# release branch push, and on demand.
 
 on:
   push:
-    branches: [main, 'release/**']
+    branches: ['release/**']
+  schedule:
+    - cron: '0 19 * * *'
   workflow_dispatch:
+    inputs:
+      runner:
+        description: Where the build runs. github is the fallback while the self-hosted Mac is offline.
+        type: choice
+        options: [self-hosted, github]
+        default: self-hosted
 
 permissions:
   contents: read
@@ -16,6 +25,9 @@ jobs:
     name: Changes (Release)
     runs-on: ubuntu-latest
     timeout-minutes: 5
+    permissions:
+      actions: read
+      contents: read
     outputs:
       run: ${{ steps.decide.outputs.run }}
     steps:
@@ -23,13 +35,35 @@ jobs:
         with:
           fetch-depth: 0
 
+      # A nightly diffs against the last nightly that ended green, built or skipped: main up to
+      # that commit is covered. A push that creates a release branch builds the cut commit, which
+      # the merge-base rule would skip.
       - name: Decide whether the Release build runs
         id: decide
         env:
-          BASE: ${{ github.event.before }}
+          EVENT: ${{ github.event_name }}
+          CREATED: ${{ github.event.created }}
+          BEFORE: ${{ github.event.before }}
+          GH_TOKEN: ${{ github.token }}
         run: |
           set -euo pipefail
-          run=$(scripts/ci/detect-changed-paths.sh --base "$BASE" release)
+          case "$EVENT" in
+            workflow_dispatch)
+              run=true
+              ;;
+            schedule)
+              base=$(gh api "repos/$GITHUB_REPOSITORY/actions/workflows/release-build.yml/runs?event=schedule&status=success&per_page=1" \
+                --jq '.workflow_runs[0].head_sha // ""')
+              run=$(scripts/ci/detect-changed-paths.sh --base "$base" release)
+              ;;
+            *)
+              if [ "$CREATED" = true ]; then
+                run=true
+              else
+                run=$(scripts/ci/detect-changed-paths.sh --base "$BEFORE" release)
+              fi
+              ;;
+          esac
           echo "run=$run" >> "$GITHUB_OUTPUT"
 
   # Reads "not false" so a failed changes job builds instead of passing.
@@ -37,7 +71,7 @@ jobs:
     name: Release Build
     needs: changes
     if: ${{ !cancelled() && needs.changes.outputs.run != 'false' }}
-    runs-on: xcode-27
+    runs-on: ${{ inputs.runner == 'github' && 'xcode-27' || fromJSON('["self-hosted", "macOS", "ARM64", "tablepro-release"]') }}
     timeout-minutes: 150
     # The tag's version settings run here first; 9999999 is the largest build at MAJOR 0 (RELEASING.md, Versions).
     env:
diff --git a/RELEASING.md b/RELEASING.md
index 9bf88d57ff..aef9ca877b 100644
--- a/RELEASING.md
+++ b/RELEASING.md
@@ -48,7 +48,7 @@ Tags go out between 13:00 and 15:00 ICT (UTC+7).
 
 ## Cutting a beta
 
-beta.1 cuts the line at the newest `main` commit whose push runs are all green; beta.N tags the line's head once the picks are on it.
+beta.1 cuts the line at the newest `main` commit a green nightly or dispatched Release Build ran on, once its push runs are green too. The push that creates the branch builds it again, and the tag's `verify` waits for that build. beta.N tags the line's head once the picks are on it.
 
 ```bash
 git fetch origin
@@ -96,7 +96,7 @@ python3 scripts/release/notes.py docs X.Y.Z --ref vX.Y.Z --mdx ../tablepro-docs/
 
 A `v*` tag runs `release.yml` and nothing else. A run is never cancelled, and every job reads the version, build and channel from `verify`.
 
-- `verify`: `version.py check` refuses a tag that breaks the grammar or the bounds; that `origin/release/<X.Y>` does not contain; whose previous tag on the line is not its ancestor; a stable X.Y.0 with no published beta, or a beta after its X.Y.0; a stable whose tree differs from its line's newest published beta outside `CHANGELOG.md` and `changelog.d/`, until a stable tag on the line has matched that beta; a `CHANGELOG.md` missing the stable's heading, or a published stable of this or the previous line below it; a stable whose tag still holds fragments in `changelog.d/`. Then it needs macOS Tests, iOS and Package Tests and Release Build green on the tag commit or the nearest first-parent commit that ran them, with no change to the files they read after it, waiting on a pending run. Last, it writes the notes.
+- `verify`: `version.py check` refuses a tag that breaks the grammar or the bounds; that `origin/release/<X.Y>` does not contain; whose previous tag on the line is not its ancestor; a stable X.Y.0 with no published beta, or a beta after its X.Y.0; a stable whose tree differs from its line's newest published beta outside `CHANGELOG.md` and `changelog.d/`, until a stable tag on the line has matched that beta; a `CHANGELOG.md` missing the stable's heading, or a published stable of this or the previous line below it; a stable whose tag still holds fragments in `changelog.d/`. Then it needs macOS Tests, iOS and Package Tests and Release Build green on the tag commit or the nearest first-parent commit that ran them, with no change to the files they read after it, waiting on a pending run. A push, nightly or dispatched run counts; a PR run builds a merge commit, so it does not. Last, it writes the notes.
 - `app` (`signing`): a GA Xcode for a stable (`setup-xcode` `require-release`), the CloudKit Production schema check, `build.sh app` (archive, export with `scripts/release/ExportOptions.plist`, universal and plugin load checks), `notarize.sh` on the app, `package.sh app`, `notarize.sh` on the DMG.
 - `plugins` (`signing`): the Dameng and HANA bridges, `build.sh plugins` (each target `registry.py targets` prints, universal, signed with Developer ID, the hardened runtime and a timestamp), one notary submission for all, `package.sh plugins` (the zips, described as the manifest will read them).
 - `github-release`: `actions/attest` attests `dist/*`; `gh release create` drafts, uploads and publishes; `gh release verify` and `verify-asset` check the published release.
diff --git a/scripts/release/test_version.py b/scripts/release/test_version.py
index ef0e8e8248..11f4a2c7fb 100644
--- a/scripts/release/test_version.py
+++ b/scripts/release/test_version.py
@@ -81,7 +81,7 @@ def __init__(self, releases=(), runs=None, jobs=None):
     def releases(self):
         return self._releases
 
-    def push_runs(self, workflow, sha):
+    def commit_runs(self, workflow, sha):
         self.run_queries.append((workflow, sha))
         snapshots = self._runs.get((workflow, sha), [[]])
         return snapshots.pop(0) if len(snapshots) > 1 else snapshots[0]
@@ -478,7 +478,8 @@ def run(command, **_):
             path = command[command.index("--jq") - 1]
             outputs = {
                 "/releases": "v0.82.0\tfalse\nplugin-oracle-v1.0.0\ttrue\n",
-                "/runs?": "11\tcompleted\tsuccess\n12\tin_progress\t\n",
+                "/runs?": ("11\tcompleted\tsuccess\tpush\n12\tin_progress\t\tschedule\n"
+                           "13\tcompleted\tsuccess\tworkflow_dispatch\n14\tcompleted\tfailure\tpull_request\n"),
                 "/jobs?": "success\n\n",
             }
             output = next(text for key, text in outputs.items() if key in path)
@@ -486,11 +487,11 @@ def run(command, **_):
 
         github = version.GitHub("Owner/Repo", run=run)
         self.assertEqual(github.releases(), [("v0.82.0", False), ("plugin-oracle-v1.0.0", True)])
-        self.assertEqual(github.push_runs("macos-tests.yml", "abc"),
-                         [("11", "completed", "success"), ("12", "in_progress", "")])
+        self.assertEqual(github.commit_runs("macos-tests.yml", "abc"),
+                         [("11", "completed", "success"), ("12", "in_progress", ""), ("13", "completed", "success")])
         self.assertEqual(github.job_conclusions("11", "macOS Tests"), ["success", ""])
         self.assertIn("--paginate", calls[0])
-        self.assertIn("repos/Owner/Repo/actions/workflows/macos-tests.yml/runs?head_sha=abc&event=push&per_page=100",
+        self.assertIn("repos/Owner/Repo/actions/workflows/macos-tests.yml/runs?head_sha=abc&per_page=100",
                       calls[1])
 
     def test_a_gh_failure_is_raised(self):
diff --git a/scripts/release/version.py b/scripts/release/version.py
index f36e467966..fabb3ba95e 100755
--- a/scripts/release/version.py
+++ b/scripts/release/version.py
@@ -27,6 +27,8 @@
 DETECTOR = "scripts/ci/detect-changed-paths.sh"
 FRAGMENTS = "changelog.d/"
 POLL_SECONDS = 60
+# A pull_request run builds a merge commit, not its head_sha; these events build the commit itself.
+COMMIT_EVENTS = ("push", "schedule", "workflow_dispatch")
 PENDING_STATUSES = {"queued", "in_progress", "waiting", "requested", "pending"}
 
 
@@ -155,12 +157,13 @@ def releases(self) -> List[Tuple[str, bool]]:
                           ".[] | [.tag_name, .draft] | @tsv", paginate=True)
         return [(tag, draft == "true") for tag, draft in (line.split("\t") for line in lines if line)]
 
-    def push_runs(self, workflow: str, sha: str) -> List[Tuple[str, str, str]]:
+    def commit_runs(self, workflow: str, sha: str) -> List[Tuple[str, str, str]]:
         lines = self._api(f"repos/{self.repository}/actions/workflows/{workflow}/runs"
-                          f"?head_sha={sha}&event=push&per_page=100",
-                          ".workflow_runs[] | [.id, .status, .conclusion // \"\"] | @tsv")
+                          f"?head_sha={sha}&per_page=100",
+                          ".workflow_runs[] | [.id, .status, .conclusion // \"\", .event] | @tsv")
         return [(run_id, status, conclusion)
-                for run_id, status, conclusion in (line.split("\t") for line in lines if line)]
+                for run_id, status, conclusion, event in (line.split("\t") for line in lines if line)
+                if event in COMMIT_EVENTS]
 
     def job_conclusions(self, run_id: str, job: str) -> List[str]:
         return self._api(f"repos/{self.repository}/actions/runs/{run_id}/jobs?filter=latest&per_page=100",
@@ -284,7 +287,7 @@ def fragment_errors(paths: List[str], version: Version) -> List[str]:
 def is_green(github: GitHub, workflow: str, job: str, sha: str,
              sleep: Callable[[float], None], log: Callable[[str], None]) -> bool:
     while True:
-        runs = github.push_runs(workflow, sha)
+        runs = github.commit_runs(workflow, sha)
         pending = [run_id for run_id, status, _ in runs if status in PENDING_STATUSES]
         if not pending:
             break