feat(webapp): finding detail sheet + feedback actions

[FelixTJDietrich]

Context

Split from #932 (read-only practices view). This issue adds the interactive layer: users can view finding details and submit feedback (APPLIED / DISPUTED / NOT_APPLICABLE).

Scope

Components to Create

Component	Purpose	API Hooks	Storybook Stories
FindingDetailSheet.tsx	Side sheet with evidence + guidance text	useGetFindingQuery	Default, Loading, LongEvidence, WithPreviousFeedback
FindingFeedbackActions.tsx	3 feedback buttons + current state	useSubmitFeedback, useGetLatestFeedbackQuery	NoFeedback, Applied, Disputed, NotApplicable, Submitting

Interaction Flow

1. User clicks a FindingsListItem (from feat(webapp): integrate practice findings into profile view + practices-first home redirect #932)
2. FindingDetailSheet opens as a side sheet
3. Sheet shows: practice name, verdict badge, evidence text, guidance text, PR link
4. Bottom: FindingFeedbackActions with 3 buttons
5. Feedback submission: optimistic update, toast on success/error
6. Sheet can be dismissed by clicking outside or pressing Escape

States

• Loading: <Skeleton> in sheet body while finding detail loads
• No feedback yet: All 3 buttons in neutral state
• Feedback submitted: Active button highlighted, others dimmed
• Submitting: Active button shows spinner, all disabled
• Error: toast.error("Failed to submit feedback"), buttons re-enabled

UI Conventions

• Named function exports, destructured props, export interface ComponentNameProps
• Container/presentational split: sheet opened from route or PracticesView container, detail component receives finding data as props
• Use existing Sheet / SheetContent / SheetHeader from components/ui/sheet.tsx (or Dialog if sheet doesn't exist — check codebase)
• Feedback buttons: use Button with variant prop, not custom styled divs
• cn() for class merging
• No React.FC

Storybook Requirements

• CSF3 with satisfies Meta, tags: ["autodocs"]
• fn() for all callbacks (onSubmitFeedback, onDismiss)
• Sheet story needs a decorator for proper rendering context
• Stories cover all feedback states

Verification

• Clicking a finding opens detail sheet
• Evidence and guidance text render correctly
• Feedback buttons submit and update state
• Optimistic update works (button state changes immediately)
• Error rollback works (state reverts on failure)
• Sheet dismissal works (click outside, Escape)
• All stories render correctly in Storybook