feat(inventory): photo-first drafts + on-device OCR (digitization R2+R4)

Lower the bulk-digitization cliff with two more routes on top of the
already-landed CSV import and "save and add another":

- Photo-first drafts (capture now, catalogue later): burst-capture
  photos (camera or multi-gallery) into unnamed draft varieties, shown
  in a "to catalogue" tray, hidden from the main list until named.
  Adds Variety.isDraft (schema), addDraftVariety/watchDrafts/nameDraft,
  the triage sheet and the inventory banner.
- On-device OCR label suggestion (Tesseract, offline, no Google): a
  "Suggest name from photo" button in the naming dialog behind a
  LabelTextExtractor interface (Tesseract on Android/iOS, no-op
  elsewhere). Reads the largest print via hOCR bounding boxes, drops
  boilerplate/low-confidence noise, preprocesses (grayscale, contrast,
  upscale) and sweeps rotations (0-315 deg) so tilted packets still
  read. Bundles tessdata_fast eng+spa; validated on-device against real
  packets. The photo is written to a temp file deleted immediately in a
  finally block (the plugin needs a path) - a bounded, documented
  exception to no-plaintext-at-rest.

This commit also carries the co-developed schema evolution v5 to v8 that
shares these files (organic flag, species viability years, crop
calendar, lot provenance/abundance/preservation format, condition
checks) plus their exports/migrations and i18n.

Tests: CSV/draft/OCR unit + widget + migration green in isolation.
Note: the full widget suite currently hangs (>10 min) - under investigation.

apps/app_seeds/test/services/ocr/ocr_language_test.dart

@@ -0,0 +1,100 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:tane/services/ocr/ocr_language.dart';
+
+void main() {
+  group('parseAvailableOcrLanguages', () {
+    test('strips the .traineddata suffix', () {
+      final available = parseAvailableOcrLanguages(
+        '{"files": ["eng.traineddata", "spa.traineddata"]}',
+      );
+      expect(available, {'eng', 'spa'});
+    });
+
+    test('empty / missing files yields empty set', () {
+      expect(parseAvailableOcrLanguages('{}'), isEmpty);
+      expect(parseAvailableOcrLanguages('{"files": []}'), isEmpty);
+    });
+  });
+
+  group('tesseractCodeForLocale', () {
+    test('maps ISO 639-1 to Tesseract codes', () {
+      expect(tesseractCodeForLocale('es'), 'spa');
+      expect(tesseractCodeForLocale('en'), 'eng');
+      expect(tesseractCodeForLocale('ar'), 'ara');
+      expect(tesseractCodeForLocale('zh'), 'chi_sim');
+    });
+
+    test('accepts full locale tags and is case-insensitive', () {
+      expect(tesseractCodeForLocale('es_ES'), 'spa');
+      expect(tesseractCodeForLocale('zh-Hans-CN'), 'chi_sim');
+      expect(tesseractCodeForLocale('DE'), 'deu');
+    });
+
+    test('unmapped locale returns null', () {
+      expect(tesseractCodeForLocale('xx'), isNull);
+    });
+  });
+
+  group('resolveOcrLanguages', () {
+    const bundled = {'eng', 'spa'};
+
+    test('preferred locale comes first, baseline appended', () {
+      expect(
+        resolveOcrLanguages(preferredLocales: ['es'], available: bundled),
+        'spa+eng',
+      );
+    });
+
+    test('English preferred is not duplicated by the baseline', () {
+      expect(
+        resolveOcrLanguages(preferredLocales: ['en'], available: bundled),
+        'eng',
+      );
+    });
+
+    test('order follows preference, de-duplicated', () {
+      expect(
+        resolveOcrLanguages(
+          preferredLocales: ['es', 'en', 'es'],
+          available: bundled,
+        ),
+        'spa+eng',
+      );
+    });
+
+    test('unbundled locale falls back to the Latin baseline', () {
+      // German pack is not bundled here — degrade to eng, never fail.
+      expect(
+        resolveOcrLanguages(preferredLocales: ['de'], available: bundled),
+        'eng',
+      );
+    });
+
+    test('a future RTL/CJK pack lights up automatically once bundled', () {
+      expect(
+        resolveOcrLanguages(
+          preferredLocales: ['ar'],
+          available: {'eng', 'spa', 'ara'},
+        ),
+        'ara+eng',
+      );
+    });
+
+    test('no baseline available: falls back to every bundled pack, sorted', () {
+      expect(
+        resolveOcrLanguages(
+          preferredLocales: ['fr'],
+          available: {'spa', 'deu'},
+        ),
+        'deu+spa',
+      );
+    });
+
+    test('empty available yields empty string', () {
+      expect(
+        resolveOcrLanguages(preferredLocales: ['es'], available: const {}),
+        '',
+      );
+    });
+  });
+}