Decompose App orchestration into a hook + split Result.tsx

[s-annam]

Problem

Two surfaces have outgrown the project's own structure rules. App.tsx carries orchestration logic inline (parse state machine, handleFile, JD memo, formatBytes) instead of delegating to a hook — violating CLAUDE.md "Keep business logic in src/lib/… Extract cross-cutting interaction state into src/hooks/." And Result.tsx is ~390 LOC, well past the ~200 LOC decomposition guideline, bundling six distinct concerns in one file.

Current state

• src/App.tsx (231 LOC): ParseState union (L23-34), handleFile (L56-101), jdMatch memo (L46-54), formatBytes (L36-40), reset (L103). All interaction/orchestration state sits in the component.
• src/components/Result.tsx (390 LOC): branch + StatusPill + ParsedCard + LimitedParsingCard + AtsScoreReadout (L161-265) + LayoutFlagsList (L133-159) + Dimension (L267-316) + the inline Evidence panel (Source-PDF + extracted-text, L108-128).

Plan

1. src/hooks/useResumeAnalysis.ts — owns ParseState, handleFile (parse → score → telemetry), reset. Returns { state, handleFile, reset }. App becomes layout-only: drop zone, result region, JD card, footer. formatBytes moves to a small lib/ util (or into the hook).
   • Note: if the edit-loop issue (option A) lands, override state + recompute live here too — coordinate so this hook is the single orchestration owner.
2. Decompose Result.tsx:
   • src/components/features/EvidencePanel.tsx — the Source-PDF + extracted-text two-pane block (currently L108-128).
   • src/components/features/AtsScoreReadout.tsx — the score readout incl. Dimension (L161-316).
   • src/components/features/LayoutFlagsList.tsx — (L133-159).
   • Result.tsx keeps only the isFontsUnmappable branch + ParsedCard/LimitedParsingCard composition. StatusPill is removed in favor of shared/StatusBadge (primitives issue).
3. Pure move/extract — no behavior change. Each extracted piece keeps the same props it reads today.

Acceptance criteria

• App.tsx no longer contains the ParseState machine or handleFile body — it consumes useResumeAnalysis.
• Result.tsx is under ~200 LOC; EvidencePanel, AtsScoreReadout, LayoutFlagsList are their own files under features/.
• Rendered output is byte-identical to before (no visual/behavioral change); manual check across parsed / limited / error states.
• npm run test / npm run typecheck pass with no new warnings.

Notes

Coordinates with the shared-primitives issue (StatusBadge removal) and the edit-loop issue (hook ownership). Order: primitives → this → edit-loop, or land together.

Labels

refactor

[s-annam]

Implementation Complete — 72c9705

Acceptance Criteria

• App.tsx no longer holds ParseState/handleFile — consumes useResumeAnalysis() (state/handleFile/reset/formatBytes); now layout-only.
• Result.tsx under ~200 LOC — 390 → ~140; EvidencePanel, AtsScoreReadout (incl. Dimension), LayoutFlagsList extracted to features/.
• Byte-identical output — pure move/extract, no props dropped/reordered; 319 tests pass.
• test / typecheck pass — 319/319, tsc 0 errors, no new warnings.

Additional Changes

• formatBytes → src/lib/format-bytes.ts (re-exported from the hook).
• Result.tsx already used shared/StatusBadge (no inline StatusPill to remove).