chore(release): prepare v3.0.7

Release the sync reliability fixes for retained SDK subscriptions, paused-peer retries, outbound Git command budgeting, and self-subscriber shutdown. Move the accumulated fixes into a dated changelog section and include the shutdown fix.

Align the Cargo manifest, lockfile and NixOS module at 3.0.7. Flake packages derive the version from the manifest; grasp-audit remains at 0.2.0. This commit changes release metadata only. Tag publication and fleet deployment remain separate operations.

Validation: locked offline Cargo metadata reports the intended workspace versions; regular and static Nix packages evaluate to 3.0.7; NixOS module parsing and diff checks pass. The parent passed the focused shutdown tests and Clippy and is deployed on fi1; deployment E2E CI passed, while Rust CI was still running at preparation time.

Assisted-by: GPT-6

CHANGELOG.md

@@ -7,8 +7,17 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [3.0.7] - 2026-10-02
+
+Reduce unnecessary sync traffic, reserve Git capacity for advertised commits,
+and stop subscription discovery promptly during shutdown.
+
 ### Fixed
 
+- Stop the self-subscriber when its sync-manager consumer exits or shutdown
+  arrives, including while a startup batch is blocked. Avoid repeated
+  channel-closed errors for every remaining relay.
+
 - Count individual outbound Git commands against a shared domain budget and
   reserve capacity for advertised commits during cold archive sync. Bound
   speculative OID fetches and report explicit Git rate-limit rejections.

Cargo.lock

@@ -1356,7 +1356,7 @@ checksum = "81c353b400a5503efdcf398f11a83fb7aa84f59f5d76fc4bf5bbc1e4f5366caa"
 
 [[package]]
 name = "ngit-grasp"
-version = "3.0.6"
+version = "3.0.7"
 dependencies = [
  "anyhow",
  "async-trait",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ngit-grasp"
-version = "3.0.6"
+version = "3.0.7"
 edition = "2021"
 authors = ["ngit-grasp contributors"]
 license = "MIT"

nix/module.nix

@@ -6,7 +6,7 @@ let
   # Build ngit-grasp package (shared across all instances)
   ngit-grasp = pkgs.rustPlatform.buildRustPackage {
     pname = "ngit-grasp";
-    version = "3.0.6";
+    version = "3.0.7";
     src = ../.;
     NGIT_BUILD_REVISION = ngitGraspSourceRevision;
     cargoLock = {