Port installer bundle fallback fix from v5

docs/release-control/v6/internal/records/known-rc-issue-closure-for-ga-installer-bundle-fallback-2026-05-01.md

@@ -0,0 +1,43 @@
+# Known RC Issue Closure For GA Installer Bundle Fallback Record
+
+- Date: `2026-05-01`
+- Gate: `known-rc-issue-closure-for-ga`
+- Lane: `L1`
+- Result: `passed`
+
+## Context
+
+The v5 maintenance audit found that `release/5.1` had removed an eager
+universal-bundle fallback from the root installer. The old fallback attempted
+to download `pulse-${version}.tar.gz` during install when every cross-arch
+agent binary was not already present locally.
+
+The v6 root installer still carried the same fallback for unified-agent
+binaries. That made a normal install perform an unnecessary second network
+lookup for a non-arch bundle and could produce a confusing warning even after
+the actual platform archive had installed successfully.
+
+## Disposition
+
+The v6 installer now matches the maintenance-line behavior:
+
+- bundled unified-agent binaries are still copied from the extracted release
+  archive when present;
+- the installer no longer tries to download a universal cross-architecture
+  agent bundle during the main install path;
+- missing unified-agent binaries are left for the on-demand agent install path
+  instead of making the server installer depend on a fallback release asset.
+
+This is the canonical root fix for RC3 because the install-time dependency was
+owned by the release installer, not by downstream agent setup commands.
+
+## Proof
+
+- `go test ./scripts/installtests -run 'TestInstallAdditionalAgentBinaries|TestResolveInstallScriptDownloadURL|TestInstallSHRequiresPinnedSignatureVerificationForReleaseDownloads' -count=1`
+- `bash -n install.sh`
+- `git diff --check`
+
+## Outcome
+
+The v5 installer bundle-fallback fix is ported to the current v6 candidate. The
+`known-rc-issue-closure-for-ga` gate remains satisfied for this slice.

docs/release-control/v6/internal/status.json

@@ -2476,6 +2476,11 @@
           "path": "docs/release-control/v6/internal/HIGH_RISK_RELEASE_VERIFICATION_MATRIX.md",
           "kind": "file"
         },
+        {
+          "repo": "pulse",
+          "path": "docs/release-control/v6/internal/records/known-rc-issue-closure-for-ga-installer-bundle-fallback-2026-05-01.md",
+          "kind": "file"
+        },
         {
           "repo": "pulse",
           "path": "docs/release-control/v6/internal/subsystems/deployment-installability.md",
@@ -4388,6 +4393,12 @@
           "kind": "file",
           "evidence_tier": "managed-runtime-exercise"
         },
+        {
+          "repo": "pulse",
+          "path": "docs/release-control/v6/internal/records/known-rc-issue-closure-for-ga-installer-bundle-fallback-2026-05-01.md",
+          "kind": "file",
+          "evidence_tier": "managed-runtime-exercise"
+        },
         {
           "repo": "pulse",
           "path": "docs/release-control/v6/internal/records/known-rc-issue-closure-for-ga-late-issue-intake-2026-05-01.md",