Harden integration setup and add project memory hooks

[Daliys]

Summary

• Prevent the Integrations Auto Setup handler from throwing when its refreshed client list no longer contains the clicked client.
• Add a focused lookup regression test and changelog entry.
• Add tracked ProjectMem configuration and local Git hook wrappers.

Root cause

Auto Setup regenerated the integration list after bridge deployment and selected the original client kind with First(...). A changed list caused an unhandled InvalidOperationException.

Impact

Auto Setup now gives a clear refresh-and-retry message instead of crashing. ProjectMem runtime state remains local while the reviewed configuration and hooks are versioned.

Validation

• PYTHONDONTWRITEBYTECODE=1 scripts/prepush-validate.sh --static-only
• Push-hook validation: 34 Python bridge tests, metadata checks, and Nexus quality gate.

Closes #75.