GEDCOM: duplicate-aware import + typed name/attribute mapping

Duplicate detection (the "merge / skip / overwrite" the user asked for):
- New POST /gedcom/preview dry-runs the file and flags incoming people that
  resemble existing ones (name similarity via difflib + birth-year guard;
  high/medium score). No writes.
- /gedcom/import takes default_action (new|skip|merge|overwrite) + per-xref
  resolutions {xref: {action, target_id}}:
    new       create as a new person (current behavior)
    skip      link families to the existing person, copy nothing
    merge     attach the incoming names (as alternates), events, citations,
              and notes onto the existing person
    overwrite soft-delete the existing person, import the incoming one fresh
  Relationship creation is deduped so a merge can't double an edge.

Richer record mapping (covers the user's repo's GEDCOM):
- Multiple NAME records honor their TYPE; _MARNM (and NICK) import as typed
  alternate names — maiden stays primary, married becomes a "married" Name.
- RELI -> a "religion" event with the value in detail; OCCU/EDUC values too.
- NOTE -> person notes (and event notes); NOTE/RELI are no longer "unmapped".
- Export round-trips name TYPE.

Verified against the user's 2185-person export: 0 unmapped tags. 48 tests pass.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/lib/api/schema.d.ts

@@ -557,6 +557,27 @@ export interface paths {
         patch: operations["update_media_api_v1_trees__tree_id__media__media_id__patch"];
         trace?: never;
     };
+    "/api/v1/trees/{tree_id}/gedcom/preview": {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        get?: never;
+        put?: never;
+        /**
+         * Preview Gedcom
+         * @description Dry run: report counts and incoming people that look like duplicates of
+         *     existing ones, so the user can choose how to resolve each before importing.
+         */
+        post: operations["preview_gedcom_api_v1_trees__tree_id__gedcom_preview_post"];
+        delete?: never;
+        options?: never;
+        head?: never;
+        patch?: never;
+        trace?: never;
+    };
     "/api/v1/trees/{tree_id}/gedcom/import": {
         parameters: {
             query?: never;
@@ -566,7 +587,12 @@ export interface paths {
         };
         get?: never;
         put?: never;
-        /** Import Gedcom */
+        /**
+         * Import Gedcom
+         * @description Import a GEDCOM. ``default_action`` (new|skip|merge|overwrite) applies to
+         *     incoming people that match an existing one; ``resolutions`` is a JSON object
+         *     {xref: {action, target_id}} overriding it per record.
+         */
         post: operations["import_gedcom_api_v1_trees__tree_id__gedcom_import_post"];
         delete?: never;
         options?: never;
@@ -599,6 +625,21 @@ export interface components {
         Body_import_gedcom_api_v1_trees__tree_id__gedcom_import_post: {
             /** File */
             file: string;
+            /**
+             * Default Action
+             * @default new
+             */
+            default_action?: string;
+            /**
+             * Resolutions
+             * @default {}
+             */
+            resolutions?: string;
+        };
+        /** Body_preview_gedcom_api_v1_trees__tree_id__gedcom_preview_post */
+        Body_preview_gedcom_api_v1_trees__tree_id__gedcom_preview_post: {
+            /** File */
+            file: string;
         };
         /** Body_upload_media_api_v1_trees__tree_id__media_post */
         Body_upload_media_api_v1_trees__tree_id__media_post: {
@@ -683,6 +724,26 @@ export interface components {
             detail?: string | null;
             confidence?: components["schemas"]["CitationConfidence"] | null;
         };
+        /** DuplicateMatch */
+        DuplicateMatch: {
+            /** Xref */
+            xref: string;
+            /** Incoming Name */
+            incoming_name: string;
+            /** Incoming Birth Year */
+            incoming_birth_year?: string | null;
+            /**
+             * Existing Person Id
+             * Format: uuid
+             */
+            existing_person_id: string;
+            /** Existing Name */
+            existing_name: string;
+            /** Existing Birth Year */
+            existing_birth_year?: string | null;
+            /** Score */
+            score: string;
+        };
         /** EventCreate */
         EventCreate: {
             /** Event Type */
@@ -777,6 +838,17 @@ export interface components {
             /** Detail */
             detail?: components["schemas"]["ValidationError"][];
         };
+        /** ImportPreview */
+        ImportPreview: {
+            /** Counts */
+            counts: {
+                [key: string]: number;
+            };
+            /** Potential Duplicates */
+            potential_duplicates: components["schemas"]["DuplicateMatch"][];
+            /** Unmapped Tags */
+            unmapped_tags: string[];
+        };
         /** ImportReport */
         ImportReport: {
             /** Counts */
@@ -2845,6 +2917,41 @@ export interface operations {
             };
         };
     };
+    preview_gedcom_api_v1_trees__tree_id__gedcom_preview_post: {
+        parameters: {
+            query?: never;
+            header?: never;
+            path: {
+                tree_id: string;
+            };
+            cookie?: never;
+        };
+        requestBody: {
+            content: {
+                "multipart/form-data": components["schemas"]["Body_preview_gedcom_api_v1_trees__tree_id__gedcom_preview_post"];
+            };
+        };
+        responses: {
+            /** @description Successful Response */
+            200: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content: {
+                    "application/json": components["schemas"]["ImportPreview"];
+                };
+            };
+            /** @description Validation Error */
+            422: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content: {
+                    "application/json": components["schemas"]["HTTPValidationError"];
+                };
+            };
+        };
+    };
     import_gedcom_api_v1_trees__tree_id__gedcom_import_post: {
         parameters: {
             query?: never;