Fix dangling release guide link in AGENTS.md

The release guide was refactored from a single contrib/claude/release.md
into a contrib/claude/release/ directory with a README index and per-track
guides, but the AGENTS.md link was never updated and pointed at a missing
file. Repoint it to release/README.md. CLAUDE.md is a symlink to AGENTS.md,
so it inherits the fix.

Signed-off-by: Sacha Al Himdani <sacha@probo.com>

AGENTS.md

@@ -30,6 +30,6 @@ Detailed guides for specific subsystems live in `contrib/claude/`:
 - [`contrib/claude/prompt-style.md`](contrib/claude/prompt-style.md) — Agent prompt template structure (role/task/instructions XML style)
 - [`contrib/claude/commit.md`](contrib/claude/commit.md) — Commit message conventions
 - [`contrib/claude/license.md`](contrib/claude/license.md) — ISC license header (all file types)
-- [`contrib/claude/release.md`](contrib/claude/release.md) — Release process (version bump, changelog, tag, push)
+- [`contrib/claude/release/README.md`](contrib/claude/release/README.md) — Release process (per-track version bump, changelog, tag, push)
 - [`contrib/claude/sandbox.md`](contrib/claude/sandbox.md) — Lima sandbox environments (create, manage, access services)
 - [`contrib/claude/n8n.md`](contrib/claude/n8n.md) — n8n community node (resources, operations, GraphQL helpers)