Missing rollback call after DB rename failure

[asmit25805]

name: Bug Report
description: Report a reproducible bug in Odysseus.
labels: ["bug"]

body:

• type: markdown
  attributes:
  value: |
  Before submitting: search open issues
  and discussions first.
  Duplicate reports slow things down.

  For security vulnerabilities, **do not open a public issue** —
  use [GitHub Security Advisories](https://github.com/pewdiepie-archdaemon/odysseus/security/advisories/new)
  and read [SECURITY.md](https://github.com/pewdiepie-archdaemon/odysseus/blob/main/SECURITY.md) first.
  

• type: checkboxes
  id: prerequisites
  attributes:
  label: Prerequisites
  options:
  - label: I searched open issues and discussions and did not find an existing report of this bug.
  required: true
  - label: This is not a security vulnerability. (Vulnerabilities go to GitHub Security Advisories — see SECURITY.md.)
  required: true
  - label: I am running the latest code from the dev branch (the default branch you get on clone, where fixes land first) and the bug still reproduces there. Please git pull the latest dev before filing.
  required: true

• type: dropdown
  id: install-method
  attributes:
  label: Install Method
  options:
  - "-- Please Select --"
  - Docker (docker compose up)
  - Manual Python install (pip / venv)
  - Windows native (launch-windows.ps1)
  - macOS app (build-macos-app.sh / start-macos.sh)
  - Other (describe in the reproduction steps below)
  validations:
  required: true

• type: dropdown
  id: os
  attributes:
  label: Operating System
  options:
  - "-- Please Select --"
  - Linux
  - macOS
  - Windows
  - Other
  validations:
  required: true

• type: textarea
  id: steps
  attributes:
  label: Steps to Reproduce
  description: Exact steps that reliably trigger the bug. The more specific, the faster this gets fixed.
  placeholder: |
  1. Go to ...
  2. Click / type ...
  3. Observe ...
  validations:
  required: true

• type: textarea
  id: expected
  attributes:
  label: Expected Behaviour
  description: What should have happened?
  validations:
  required: true

• type: textarea
  id: actual
  attributes:
  label: Actual Behaviour
  description: What actually happened? Include the full error message if there is one.
  validations:
  required: true

• type: textarea
  id: logs
  attributes:
  label: Logs / Screenshots
  description: Paste relevant terminal output or attach screenshots. Remove API keys, passwords, and personal data before pasting.
  render: text

• type: input
  id: model-backend
  attributes:
  label: Model / Backend (if relevant)
  description: "e.g. Ollama + llama3.2:latest, vLLM + mistral-7b, OpenAI API, Anthropic API"
  placeholder: "Ollama + llama3.2:latest"

• type: dropdown
  id: willing_to_fix
  attributes:
  label: Are you willing to submit a fix?
  options:
  - "-- Please Select --"
  - "Yes — I can open a PR"
  - "Partially — I can help but need guidance"
  - "No — I am only filing the report"
  validations:
  required: true

• type: textarea
  id: additional-info
  attributes:
  label: Additional Information
  description: Anything else that might help — browser console errors, related issues, things you already tried, or environment quirks.

File: routes/auth_routes.py — rename_user