chore(release): bump version 2.5.1 -> 2.5.2 (security patch)

Mid-week patch release for the CI/release security hardening:
least-privilege e2e-wheel token + Sigstore-signed GitHub Releases.
Bumps both pyproject.toml and src/aipass/__init__.py __version__.

Versioning scheme: patch (2.5.x) = small mid-week fixes, minor (2.x.0)
= Sunday main-merge batches.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "aipass"
-version = "2.5.1"
+version = "2.5.2"
 description = "A local multi-agent framework where your AI agents keep their memory, work together, and never ask you to re-explain context"
 readme = "README.md"
 license = "MIT"

src/aipass/__init__.py

@@ -4,4 +4,4 @@ pip install aipass
 https://github.com/AIOSAI/AIPass
 """
 
-__version__ = "2.5.1"
+__version__ = "2.5.2"