Update associated_tools type and display in server management

[arjavdongaonkar]

🐛 Bug-fix PR

Before opening this PR please:

1. make lint - passes ruff, mypy, pylint
2. make test - all unit + integration tests green
3. make coverage - ≥ 90 %
4. make docker docker-run-ssl or make podman podman-run-ssl
5. Update relevant documentation.
6. Tested with sqlite and postgres + redis.
7. Manual regression no longer fails. Ensure the UI and /version work correctly.

---

📌 Summary

Associated tools checkboxes in the Edit of virtual servers are not being pre-populated correctly.

🔁 Reproduction Steps

1. Associate a tool with a server.
2. Reopen the "Edit Server" modal.
3. Observe that no checkboxes are checked, even though the server does have associated tools.

🐞 Root Cause

The server returns a list of tool names (e.g., ["test"]), while the checkboxes use tool IDs (e.g., "6e95c70ea2cb4fdf87237e9ed6b0468b") as their values.
As a result, no checkboxes are checked even when tools are associated with the server.

💡 Fix Description

1. Change backend response for associatedTools to return a list of objects { id, name, displayName } instead of a list of strings.
2. This will require changes in multiple places across the pipeline, but it provides stable identifiers and avoids name collisions.

🧪 Verification

Check	Command	Status
Lint suite	make lint
Unit tests	make test
Coverage ≥ 90 %	make coverage
Manual regression no longer fails	steps / screenshots

📐 MCP Compliance (if relevant)

• Matches current MCP spec
• No breaking change to MCP clients

✅ Checklist

• Code formatted (make black isort pre-commit)
• No secrets/credentials committed