5563 - Replace policy spec stubs with real tests

[fuentesjr]

What github issue is this PR for, if any?

Part of #5563 — intentionally not Resolves, since the umbrella has more stubs remaining.

What changed, and why?

Replaces the four pending "add some tests for X" stubs in spec/policies/ with real specs (one commit per file), using the pundit-matchers permissions DSL and build_stubbed, following the patterns in checklist_item_policy_spec.rb and custom_org_link_policy_spec.rb:

• NotePolicy — create? / edit? / update? / destroy? (all delegate to admin_or_supervisor?): casa_admin and supervisor permitted, volunteer denied
• FundRequestPolicy — new? / create? are intentionally unconditional; the spec pins that all roles (and even a nil user) are permitted, with a NOTE explaining access is constrained upstream by FundRequestsController#verify_casa_case
• LearningHourTopicPolicy / LearningHourTypePolicy — empty policy classes; specs characterize the inherited admin-only contract (new? / create? / edit? / update?) their controllers rely on: casa_admin permitted, supervisor and volunteer denied

Coverage matches each controller's authorized actions exactly. None of these policies define a Scope or permitted_attributes, so no org-scoping specs apply.

How is this tested? (please write rspec and jest tests!) 💖💪

• bundle exec rspec spec/policies/note_policy_spec.rb spec/policies/fund_request_policy_spec.rb spec/policies/learning_hour_topic_policy_spec.rb spec/policies/learning_hour_type_policy_spec.rb → 13 examples, 0 failures, 0 pending
• bundle exec standardrb spec/policies/ → no offenses
• No pending / skip / xit remains in the four files

Screenshots please :)

N/A — test-only change, no UI.