diff --git a/scripts/__tests__/run-vitest-stable-shard.test.mjs b/scripts/__tests__/run-vitest-stable-shard.test.mjs
index ffe7fb2d0b7..05c8d8c1260 100644
--- a/scripts/__tests__/run-vitest-stable-shard.test.mjs
+++ b/scripts/__tests__/run-vitest-stable-shard.test.mjs
@@ -428,3 +428,40 @@ test("filtered collection must match the exact assigned case identities, includi
     assert.throws(() => assertSelectedTests(expected, actual, lineShardFile));
   }
 });
+
+// Release verification on master (release-verify.yml after #15619 and #15831)
+// selects the without-chat-or-native-runner server group plus a separate
+// native-runner lane, and runs the db project in its own workspaces-c lane.
+// This source predates those lanes, so the groups are mirrored here so the
+// stable promotion of this commit verifies under master's workflow contract.
+for (const caller of ["Release", "Cloud readiness", "another caller"]) {
+  test(`release server, chat, and native lanes cover every server suite once under ${caller}`, () => {
+    const env = { GITHUB_WORKFLOW: caller };
+    const full = dryRunJson(["--mode", "general", "--group", "general-server", "--shard-index", "0", "--shard-count", "1"], env);
+    const files = Array.from({ length: 10 }, (_, index) => dryRunJson([
+      "--mode", "general", "--group", "general-server-without-chat-or-native-runner",
+      "--shard-index", String(index), "--shard-count", "10",
+    ], env)).flatMap((shard) => shard.selectedGeneralServerSuites);
+    const native = dryRunJson(["--mode", "general", "--group", "general-server-native-runner"], env);
+    const combined = [...files, chatSuitePath, ...native.selectedGeneralServerSuites];
+    assert.equal(new Set(combined).size, combined.length, "lanes must not overlap");
+    assert.deepEqual(combined.sort(), full.selectedGeneralServerSuites.sort());
+  });
+}
+
+test("workspaces-c runs the db project alone and workspaces-b no longer carries it", () => {
+  const workspacesC = dryRunJson(["--mode", "general", "--group", "general-workspaces-c"]);
+  assert.deepEqual(workspacesC.workspaceProjects, ["@paperclipai/db"]);
+  assert.equal(workspacesC.workspacesVitestShard, null);
+  const workspacesB = dryRunJson(["--mode", "general", "--group", "general-workspaces-b"]);
+  assert.ok(!workspacesB.workspaceProjects.includes("@paperclipai/db"), "db must not run twice");
+  assert.ok(workspacesB.workspaceProjects.length > 0, "workspaces-b must still run its other projects");
+  const workspacesA = dryRunJson(["--mode", "general", "--group", "general-workspaces-a"]);
+  const all = [...workspacesA.workspaceProjects, ...workspacesB.workspaceProjects, ...workspacesC.workspaceProjects];
+  assert.equal(new Set(all).size, all.length, "no project may run in two workspace lanes");
+});
+
+test("shard flags are rejected for the workspaces-c group", () => {
+  const result = dryRun(["--mode", "general", "--group", "general-workspaces-c", "--shard-index", "0", "--shard-count", "3"]);
+  assert.notEqual(result.status, 0, "workspaces-c must not accept shard flags");
+});
diff --git a/scripts/run-vitest-stable.mjs b/scripts/run-vitest-stable.mjs
index d98a814a12d..6231e1dff72 100644
--- a/scripts/run-vitest-stable.mjs
+++ b/scripts/run-vitest-stable.mjs
@@ -69,6 +69,9 @@ const generalModeName = "general";
 const allModeName = "all";
 const generalServerGroupName = "general-server";
 const generalServerWithoutChatGroupName = "general-server-without-chat";
+// Release verification on master selects this explicit group (release-verify.yml
+// after #15619) and runs the native-runner suite in its cached Runner lane.
+const generalServerWithoutChatOrNativeRunnerGroupName = "general-server-without-chat-or-native-runner";
 const generalChatGroupName = "general-chat";
 const generalServerNativeRunnerGroupName = "general-server-native-runner";
 const chatSuite = "server/src/__tests__/chat-channels.integration.test.ts";
@@ -92,14 +95,35 @@ const nativeRunnerSuiteRunsInRustCachedLane = process.env.GITHUB_WORKFLOW === pr
 const withoutChatExcludedSuites = nativeRunnerSuiteRunsInRustCachedLane
   ? [chatSuite, nativeRunnerSuite]
   : [chatSuite];
+const generalServerGroups = [
+  generalServerGroupName,
+  generalServerWithoutChatGroupName,
+  generalServerWithoutChatOrNativeRunnerGroupName,
+];
+function excludedServerSuites(groupName) {
+  if (groupName === generalServerWithoutChatOrNativeRunnerGroupName) return [chatSuite, nativeRunnerSuite];
+  if (groupName === generalServerWithoutChatGroupName) return withoutChatExcludedSuites;
+  return [];
+}
 const generalWorkspacesAGroupName = "general-workspaces-a";
 const generalWorkspacesBGroupName = "general-workspaces-b";
+// The db project runs as its own lane (release-verify.yml after #15831).
+const generalWorkspacesCGroupName = "general-workspaces-c";
 const generalWorkspacesAProjects = ["@paperclipai/ui", "paperclipai"];
-const generalWorkspacesBProjects = nonServerProjects.filter((project) => !generalWorkspacesAProjects.includes(project));
-const generalGroupNames = [generalServerGroupName, generalWorkspacesAGroupName, generalWorkspacesBGroupName];
+const generalWorkspacesCProjects = ["@paperclipai/db"];
+const generalWorkspacesBProjects = nonServerProjects.filter(
+  (project) => !generalWorkspacesAProjects.includes(project) && !generalWorkspacesCProjects.includes(project),
+);
+const generalGroupNames = [
+  generalServerGroupName,
+  generalWorkspacesAGroupName,
+  generalWorkspacesBGroupName,
+  generalWorkspacesCGroupName,
+];
 const allowedGeneralGroupNames = [
   ...generalGroupNames,
   generalServerWithoutChatGroupName,
+  generalServerWithoutChatOrNativeRunnerGroupName,
   generalChatGroupName,
   generalServerNativeRunnerGroupName,
 ];
@@ -248,7 +272,7 @@ function parseCliOptions(argv) {
   const shardAllowed =
     mode === serializedModeName ||
     (mode === generalModeName &&
-      ([generalServerGroupName, generalServerWithoutChatGroupName, generalChatGroupName, generalWorkspacesAGroupName].includes(group)));
+      ([...generalServerGroups, generalChatGroupName, generalWorkspacesAGroupName].includes(group)));
   if (!shardAllowed && shardIndex !== null) {
     fail(
       "--shard-index/--shard-count are only valid with serialized mode or a shardable general server/chat/workspaces-a group.",
@@ -388,14 +412,13 @@ function runGeneralGroup(routeTests, groupName, shardIndex = null, shardCount =
     );
     return;
   }
-  if (groupName === generalServerGroupName || groupName === generalServerWithoutChatGroupName) {
+  if (generalServerGroups.includes(groupName)) {
     // In the PR workflow the without-chat group also leaves the native-runner
     // suite to the Rust-cached vitest lane; the full general-server group
-    // (local runs) keeps both.
-    const withoutChat = groupName === generalServerWithoutChatGroupName;
-    const files = withoutChat
-      ? generalServerTestFiles.filter((file) => !withoutChatExcludedSuites.includes(file))
-      : generalServerTestFiles;
+    // (local runs) keeps both. The explicit without-chat-or-native-runner
+    // group always excludes both, for callers that run those lanes separately.
+    const excludedSuites = excludedServerSuites(groupName);
+    const files = generalServerTestFiles.filter((file) => !excludedSuites.includes(file));
     if (shardCount !== null && shardCount > 1) {
       const shardFiles = selectGeneralServerShard(
         files,
@@ -423,10 +446,8 @@ function runGeneralGroup(routeTests, groupName, shardIndex = null, shardCount =
     }
 
     const excludeRouteArgs = routeTests.flatMap((file) => ["--exclude", file.serverPath]);
-    if (withoutChat) {
-      for (const suite of withoutChatExcludedSuites) {
-        excludeRouteArgs.push("--exclude", suite.replace(/^server\//, ""));
-      }
+    for (const suite of excludedSuites) {
+      excludeRouteArgs.push("--exclude", suite.replace(/^server\//, ""));
     }
     runVitest(
       [
@@ -454,6 +475,11 @@ function runGeneralGroup(routeTests, groupName, shardIndex = null, shardCount =
     return;
   }
 
+  if (groupName === generalWorkspacesCGroupName) {
+    runProjectGroup(generalWorkspacesCProjects, groupName);
+    return;
+  }
+
   fail(`Unknown group "${groupName}".`);
 }
 
@@ -519,12 +545,10 @@ if (options.dryRun) {
           options.mode === generalModeName && options.group === generalServerNativeRunnerGroupName
             ? [nativeRunnerSuite]
             : options.mode === generalModeName &&
-                [generalServerGroupName, generalServerWithoutChatGroupName].includes(options.group) &&
+                generalServerGroups.includes(options.group) &&
                 options.shardCount !== null
               ? selectGeneralServerShard(
-                  options.group === generalServerWithoutChatGroupName
-                    ? generalServerTestFiles.filter((file) => !withoutChatExcludedSuites.includes(file))
-                    : generalServerTestFiles,
+                  generalServerTestFiles.filter((file) => !excludedServerSuites(options.group).includes(file)),
                   options.shardIndex,
                   options.shardCount,
                   generalServerShardDurations,
@@ -535,7 +559,9 @@ if (options.dryRun) {
             ? generalWorkspacesAProjects
             : options.group === generalWorkspacesBGroupName
               ? generalWorkspacesBProjects
-              : null,
+              : options.group === generalWorkspacesCGroupName
+                ? generalWorkspacesCProjects
+                : null,
         workspacesVitestShard:
           options.group === generalWorkspacesAGroupName &&
           options.shardCount !== null &&