Fix resource handler to use deps from context

[SamMorrowDrums]

The RepositoryResourceContentsHandler was using closure-captured deps instead of retrieving them from context at call time. This causes issues on the remote server which injects per-request deps via context.

Changes

• Changed RepositoryResourceContentsHandler to use MustDepsFromContext(ctx) pattern consistent with tool handlers in NewTool and NewToolFromHandler
• Removed deps parameter from function signature (now only takes resourceURITemplate)
• Updated tests to inject deps via ContextWithDeps before calling the handler

Testing

• All existing tests pass
• Lint passes

[Copilot]

Pull request overview

This PR fixes the RepositoryResourceContentsHandler to retrieve dependencies from context at call time instead of using closure-captured dependencies. This change enables the remote server to inject per-request dependencies via context, aligning resource handlers with the existing pattern used by tool handlers.

Key Changes:

• Modified RepositoryResourceContentsHandler to use MustDepsFromContext(ctx) instead of accepting deps as a parameter
• Updated repositoryResourceContentsHandlerFunc to ignore the deps parameter and call the simplified handler
• Updated all test cases to inject dependencies via ContextWithDeps before handler invocation

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
pkg/github/repository_resource.go	Changed handler to retrieve deps from context using MustDepsFromContext(ctx), removed deps parameter from function signature, updated doc comment
pkg/github/repository_resource_test.go	Updated test setup to inject deps via ContextWithDeps, changed handler function signatures to remove deps parameter, passed context to handler calls