docs(legibility): add 18 per-domain README.md files (DOC-6)

Backend (9): document, person, tag, user, geschichte, notification,
ocr, audit, dashboard.
Frontend (8): document, person, tag, user, geschichte, notification,
ocr, shared.
OCR service (1): ocr-service/README.md.

Each README covers: what the domain owns, explicit non-ownership,
public surface (verified by grep against the codebase), internal
layout, and cross-domain dependencies.

Closes #400
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/lib/person/README.md

@@ -0,0 +1,37 @@
+# person (frontend)
+
+UI for historical family members: typeahead selection, chip display, hover cards, genealogy graph, relationship management.
+
+## What this domain owns
+
+Components: `PersonTypeahead.svelte`, `PersonMultiSelect.svelte`, `PersonChip.svelte`, `PersonChipRow.svelte`, `PersonHoverCard.svelte`, `PersonTypeBadge.svelte`, `PersonTypeSelector.svelte`.
+Utilities: `personFormat.ts` (full-name formatting), `personLifeDates.ts` (birth/death display), `person-validation.ts` (form validation), `personHoverCard.ts` (hover-card controller).
+Sub-folders: `genealogy/` (Stammbaum view components), `relationship/` (relationship graph components).
+
+## What this domain does NOT own
+
+- Document content — displayed in `document/`
+- AppUser accounts — managed in `user/`
+
+## Key components
+
+| Component                  | Used in                                   | Notes                                                                               |
+| -------------------------- | ----------------------------------------- | ----------------------------------------------------------------------------------- |
+| `PersonTypeahead.svelte`   | document edit, geschichte, search filters | Single-person selector with debounced typeahead. Exported for use by other domains. |
+| `PersonMultiSelect.svelte` | document edit (receivers)                 | Chip-based multi-person selector                                                    |
+| `PersonChip.svelte`        | document rows, conversation view          | Compact display chip with link and hover card                                       |
+| `PersonHoverCard.svelte`   | person chips                              | Floating card with person summary on hover                                          |
+
+## Cross-domain imports
+
+- `shared/primitives/` — generic UI primitives
+- `shared/hooks/useTypeahead.svelte.ts` — typeahead keyboard/focus logic
+
+## Accessibility notes
+
+- `PersonChip` focus ring: `focus-visible:ring-2 focus-visible:ring-brand-navy`
+- `PersonTypeahead` dropdown navigable via keyboard (↑↓ Enter Escape)
+
+## Backend counterpart
+
+`backend/src/main/java/org/raddatz/familienarchiv/person/README.md`