Ten source files over 580 lines, with a suggested split for each

## What happens

The ten largest files in `Sources/` on origin/main, with one seam each that moves a self-contained part out. Line ranges are approximate starting points, not a prescription.

| Lines | File | Suggested seam |
|---|---|---|
| 1,930 | `Sources/Uttrflow/AppDelegate.swift` | The second `// MARK: The clipboard` block (about 648-1128: watching, the quick panel, `carryOut(PanelChange/PanelIntent)`, insert and paste) into `AppDelegate+Clipboard.swift`; the private store adapters at the end (about 1845-1930: `DictionaryCorrections`, `StoredSnippets`, `StoreCounters`, `LearnedVocabulary`) into their own file where they can be tested. The `MARK: The clipboard` label appears twice (lines 73 and 648). |
| 1,631 | `Sources/UttrflowEval/EvaluationCorpus.swift` | Pure data: `contextual` (about 607-1418) into `EvaluationCorpus+Contextual.swift` as an extension (#631). |
| 1,083 | `Sources/Uttrflow/Panel/QuickPanelView.swift` | `// MARK: - Sheets` (about 719-902) into a `QuickPanelSheets` view; `RightClickWatch` and `PointerWatch` (about 965-1040) into their own file. |
| 848 | `Sources/UttrflowPipeline/DictationPipeline.swift` | The stages after transcription (`correct`, `tidy`, `finishMessage`, `expand`, about 615-700) and the helper extensions at the end into `DictationPipeline+Cleaning.swift`. |
| 770 | `Sources/Uttrflow/Suggestion/SuggestionCoordinator.swift` | `SuggestionReason` and the snapshot-to-model mappers (`situation(of:for:store:)`, `reading(of:)`, `context(of:at:)`) into a builder outside the main-actor loop. |
| 750 | `Sources/UttrflowUX/SettingsPresenter.swift` | `// MARK: - Suggestions` (about 343-539) into `SettingsPresenter+Suggestions.swift`. |
| 729 | `Sources/UttrflowClipboard/RichTextPlainForm.swift` | The HTML tokenizer and entity tables (about 18-346) into `HTMLTokenizer.swift`, testable without rendering. |
| 728 | `Sources/UttrflowAI/MeaningPreservationGuard.swift` | `// MARK: Checks` for numbers (about 585-728) into `NumberPreservation.swift`. |
| 689 | `Sources/UttrflowLocalModel/MLXCandidateScorer.swift` | The text helpers that never touch MLX (about 235-292 and 404-597) into a file tests can reach without linking MLX. |
| 678 | `Sources/UttrflowUX/PanelPresentation.swift` | The empty-state logic (about 551-678) into `PanelEmptyState.swift`. |

## Why it matters

Files this size are where a newcomer gets lost and where two pull requests collide. Four of them (`AppDelegate`, `QuickPanelView`, `SuggestionCoordinator`, `MLXCandidateScorer`) are also excluded from coverage whole, so a split that moves logic out is also a split that brings it under the floor.

## Acceptance criteria

- One pull request per file, each a move with no behaviour change, and `make verify` green.
- Splits of files with open work against them wait for that work: #572 and #573 add cases to `EvaluationCorpus.swift`.
- Tick the file off here when its split lands.

Choose one source file from the table and read its suggested seam, checking for open work before starting; #572 and #573 affect EvaluationCorpus.swift. Move only the named self-contained section into the proposed file, preserving behavior, then run make verify. Tick the selected file off when its split lands.

Written by the indexing model from the issue text.