feat: create CodeRepos class

[CasLubbers]

This PR is the first step in breaking down the OtomiStack God Object into smaller, cohesive domain classes.

What was done
Extracted all Code Repository–related logic into a new CodeRepos domain class
Introduced a Deployer class to encapsulate deployment-related logic
Updated route handlers to use:

req.otomi.codeRepos.<method>()

instead of calling methods directly on OtomiStack

Added an explicit initialization method to wire dependencies:

initDomain() {
  this.deployer = new Deployer(this.git, this.fileStore, this.editor, this.sessionId)
  this.codeRepos = new CodeRepos(this.fileStore, this.deployer)
}

Design choices

• Facade pattern preserved
• OtomiStack remains the session-scoped entry point (req.otomi)
• Explicit initialization over lazy loading
• Domain objects are created via initDomain() after infrastructure (git, fileStore) is ready, instead of using lazy-loaded getters
• Use composition:
  • Domain classes are instantiated using new to keep the initial refactor simple and avoid premature abstraction

Open questions / follow-ups

• Should we switch to lazy-loaded getters to defer object creation?
• Do we want to evolve this into a more formal composition root pattern (e.g. factory/builder) to guarantee fully-initialized objects?
  Next steps
• Continue extracting other domains (e.g. Builds, Teams, etc.) following the same pattern
• Re-evaluate initialization strategy (lazy vs explicit) once more domains are migrated