fix(app): display prerequisites on edit screen

[TheGIftedExplorer]

Summary

Made the prerequisite guides(both exising and to-do) visible on the Edit Guide screen without allowing them to be modified. Added a prop showPrerequisiteFields to separate visibility from editability

Type of change

• Bug fix
• Feature
• Refactor (no behavior change)
• Documentation
• Build / tooling / CI
• Other: _________

Verification

• pnpm -r typecheck passes
• pnpm -r build passes
• Manually verified in a browser (for UI / behavior changes)
• Followed the app layout conventions
• No new dependencies, or new dependencies are justified and AGPL-compatible
• Change does not violate any non-negotiable principle
• Documentation only, no changes to the codebase, so no tests required

Closes #363 #321

[andyrodrigues30]

@TheGIftedExplorer - Both prerequisite guides and todo prerequisite guides fields should be editable, right now the fields are disabled.

[andyrodrigues30]

@TheGIftedExplorer - is there an update on this PR?

[TheGIftedExplorer]

@andyrodrigues30 Worked with this graph API I came across
Added a GET endpoint to fetch prerequisite graph edges
Added the corresponding frontend API helpers
Updated the guide edit flow to sync prerequisite changes through the graph API instead of syncDraftTagsAndEdges().
Adding new prerequisites works correctly in an updated draft but while testing removal of an existing prerequisite, I found that the frontend sync logic attempts to remove the edge, but the database RLS only allows moderators/admins to update guide_edges.

There may be an intended workflow I'm missing. I am leaving this issue for someone with good understanding of the backend