Configure automated dependency update workflows

[GuiBibeau]

User Story

As a maintainer, I want dependency update automation so that the project stays current without relying on ad hoc manual upgrades.

Context

A fellowship project should model healthy maintenance practices. This issue should introduce automated dependency update tooling and a sensible review strategy.

Acceptance Criteria

• Dependency update automation is configured for the repo
• Update PRs are grouped or structured in a sensible way
• The workflow is documented so contributors understand how updates are handled
• The automation works with the project's CI checks
• The configuration avoids excessive PR spam

Notes

• Favor maintainability and clarity over maximal automation
• Think about frontend, testing, and tooling dependencies separately if helpful
• This should reduce maintenance burden, not create noise

Out of Scope

• Automatic merging of all updates
• Large manual dependency migrations

Size

Medium