feat: allow owner to toggle collaborator permissions in ShareDialog

[calebyhan]

Description

Users can change shared permissions.

Type of Change

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📚 Documentation update
• 🔨 Refactoring (no functional changes)
• ✅ Test additions or updates
• 🔧 Configuration/build changes

Related Issues

Closes #58

Changes Made

• Added UpdateCollaboratorRequest Pydantic model
• Added PATCH /api/canvases/{canvas_id}/collaborators/{collab_user_id} — owner-only endpoint that updates a collaborator's permission in the canvas_collaborators table
• Added canvasAPI.updateCollaboratorPermission() calling the new PATCH endpoint
• Added handleUpdatePermission handler
• Replaced the static Badge with a clickable toggle button — clicking it flips the collaborator's permission between view/edit inline, with distinct styling for each state

Checklist

• My code follows the project's style guidelines (PEP 8 for Python, ESLint for TypeScript)
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings or errors
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published

Additional Context

N/A

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[Copilot]

Pull request overview

Adds owner-only support for changing an existing collaborator’s permission (view/edit) from the Share dialog, backed by a new backend PATCH endpoint.

Changes:

• Backend: add PATCH /api/canvases/{canvas_id}/collaborators/{collab_user_id} to update a collaborator’s permission (owner-only).
• Frontend API client: add canvasAPI.updateCollaboratorPermission() wrapper for the new endpoint.
• UI: replace the collaborator permission badge with an inline toggle button that flips view/edit and updates local state.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
frontend/lib/api/backendClient.ts	Adds an API helper to call the new collaborator-permission PATCH endpoint.
frontend/components/canvas/ShareDialog.tsx	Adds permission-toggle UI and handler to update a collaborator’s permission inline.
backend/app/api/routes/canvases.py	Introduces request model + owner-only PATCH route to update canvas_collaborators.permission.

[Copilot]

Pull request overview

Adds an owner-only capability to change an existing collaborator’s permission (view/edit) from the Share dialog, backed by a new backend PATCH endpoint and corresponding frontend API call.

Changes:

• Backend: introduce UpdateCollaboratorRequest and add PATCH /api/canvases/{canvas_id}/collaborators/{collab_user_id} (owner-only) to update a collaborator’s permission.
• Frontend: add canvasAPI.updateCollaboratorPermission() and update ShareDialog to toggle a collaborator’s permission inline.
• Tests: add route-level pytest coverage for the new PATCH endpoint (success, forbidden, not-found).

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
frontend/lib/api/backendClient.ts	Adds a typed client wrapper for the new collaborator-permission PATCH endpoint.
frontend/components/canvas/ShareDialog.tsx	Adds a click-to-toggle UI to flip collaborator permission between view/edit.
backend/app/api/routes/canvases.py	Adds request model + owner-only PATCH route to update collaborator permissions.
backend/tests/api/routes/test_api_canvases_full.py	Adds tests for success/403/404 behaviors of the new endpoint.

[Copilot]

Pull request overview

This PR adds end-to-end support for canvas owners to toggle a collaborator’s permission between view and edit directly from the Share dialog, backed by a new owner-only backend PATCH endpoint and a frontend API wrapper.

Changes:

• Added PATCH /api/canvases/{canvas_id}/collaborators/{collab_user_id} (owner-only) to update a collaborator’s permission in canvas_collaborators.
• Added canvasAPI.updateCollaboratorPermission() to call the new endpoint.
• Updated ShareDialog to replace the static permission badge with an inline, disabled-while-updating permission toggle button.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
frontend/lib/api/backendClient.ts	Adds a typed client method to PATCH collaborator permission.
frontend/components/canvas/ShareDialog.tsx	Adds UI + handler/state for inline permission toggling per collaborator.
backend/app/api/routes/canvases.py	Adds request model and owner-only PATCH route to update collaborator permission.
backend/tests/api/routes/test_api_canvases_full.py	Adds tests for success/403/404 cases of the new PATCH route.