chore: prepare release 3.0.0

Motivation: The v3 storage, security, private-repository, and proactive-sync changes have completed production migration and integrity-check validation.

Approach: Promote the accumulated changelog entries to 3.0.0, polish the major-release summary, advance comparison links, and align Cargo plus the NixOS module package versions.

Correctness: Cargo metadata and both Nix package evaluations report 3.0.0, matching the version required by the tag-triggered release workflow.

Excluded scope: This commit does not create the v3.0.0 tag, publish release assets, change runtime behavior, or modify deployment pins.

Validation: git diff --check; cargo metadata --locked; nix eval for ngit-grasp and static package versions. No build or tests were run for this metadata-only change.

CHANGELOG.md

@@ -7,15 +7,23 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [3.0.0] - 2026-08-20
+
 ### Summary
 
-Private Repos - via private grasp service (grasp-08) - initially self-hosted only but the intention is to allow providers to offer it as service.
+ngit-grasp 3.0.0 adds self-hosted private repositories through GRASP-08, with
+the protocol designed so hosting providers can offer managed private services
+later.
 
-Proactive Sync Plus (GRASP-03) - a big enabler for maintainer based moderation and simplier and more performant git nostr clients.
+Proactive Sync Plus (GRASP-03) enables maintainer-based moderation and simpler,
+more performant Nostr Git clients.
 
-Performance and Security fixes - along with other improvements; immediate upgrade recommended; some breaking changes make v2-v3 a one way street!
+This major release also includes significant security and performance fixes;
+an immediate upgrade is recommended. Its Git storage migration makes the
+v2-to-v3 upgrade one-way without restoring a pre-upgrade snapshot.
 
-Expect a bit of downtime as a git data migraiton is performed on startup. The largest grasp service relay.ngit.dev took 50mins.
+Plan for downtime while the first v3 startup migrates Git data. The largest
+GRASP service tested so far, `relay.ngit.dev`, took approximately 51 minutes.
 
 ### Breaking changes
 
@@ -563,7 +571,8 @@ defensive limits explicit and operator-configurable.
 
 Initial release of ngit-grasp, a GRASP relay implementation in Rust.
 
-[unreleased]: https://gitworkshop.dev/npub15qydau2hjma6ngxkl2cyar74wzyjshvl65za5k5rl69264ar2exs5cyejr/ngit-grasp/compare/v2.1.2...HEAD
+[unreleased]: https://gitworkshop.dev/npub15qydau2hjma6ngxkl2cyar74wzyjshvl65za5k5rl69264ar2exs5cyejr/ngit-grasp/compare/v3.0.0...HEAD
+[3.0.0]: https://gitworkshop.dev/npub15qydau2hjma6ngxkl2cyar74wzyjshvl65za5k5rl69264ar2exs5cyejr/ngit-grasp/compare/v2.1.2...v3.0.0
 [2.1.2]: https://gitworkshop.dev/npub15qydau2hjma6ngxkl2cyar74wzyjshvl65za5k5rl69264ar2exs5cyejr/ngit-grasp/compare/v2.1.1...v2.1.2
 [2.1.1]: https://gitworkshop.dev/npub15qydau2hjma6ngxkl2cyar74wzyjshvl65za5k5rl69264ar2exs5cyejr/ngit-grasp/compare/v2.1.0...v2.1.1
 [2.1.0]: https://gitworkshop.dev/npub15qydau2hjma6ngxkl2cyar74wzyjshvl65za5k5rl69264ar2exs5cyejr/ngit-grasp/compare/v2.0.0...v2.1.0

Cargo.lock

@@ -1319,7 +1319,7 @@ checksum = "f0efe882e02d206d8d279c20eb40e03baf7cb5136a1476dc084a324fbc3ec42d"
 
 [[package]]
 name = "ngit-grasp"
-version = "2.1.2"
+version = "3.0.0"
 dependencies = [
  "anyhow",
  "async-trait",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ngit-grasp"
-version = "2.1.2"
+version = "3.0.0"
 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 = "2.1.2";
+    version = "3.0.0";
     src = ../.;
     NGIT_BUILD_REVISION = ngitGraspSourceRevision;
     cargoLock = {