Vocab study — noun & adjective flashcards with CEFR level toggles

Add SRS-driven noun and adjective flashcards modeled on the existing verb
flashcard flow:

- SharedModels/Lexeme — catalog of non-verb vocab, frequency-ranked, with
  gender for nouns and optional example sentences. Seeded from a bundled
  vocab_lexemes.json built by Scripts/vocab/build_lexemes.py, which joins
  frequency.csv + es-en.data from a pinned doozan/spanish_data commit
  (CC-BY-SA: hermitdave/FrequencyWords + Wiktionary). 1,449 nouns and 600
  adjectives, each with Wiktionary-sourced gender and (where available)
  an example sentence with English translation.
- LexemeReviewCard + LexemeReviewStore — cloud-synced SM-2 SRS, keyed by
  partOfSpeech + lexemeId + drillMode so future drill modes can coexist.
- LexemeSessionQueue + LexemePool — parallel to VocabSessionQueue; fresh
  cards sort by frequency rank.
- LexemeStudyGroup — cloud-synced resumable session per
  (partOfSpeech, drillMode).
- NounFlashcardPracticeView + AdjectiveFlashcardPracticeView — same flow
  as VocabFlashcardPracticeView: English prompt → tap to reveal Spanish
  → Again/Hard/Good/Easy. Nouns reveal with their article (la taza, el
  problema) so gender is taught alongside meaning, not as a separate
  quiz. Example sentence shown when present.

CEFR-style level toggles:
- LexemeLevel enum (A1/A2/B1/B2/C1+) derived from frequencyRank with
  standard Spanish-frequency-dictionary cutoffs (250/500/1000/2000).
- UserProgress.selectedLexemeLevels — cloud-synced multi-select, defaults
  to A1+A2 on first launch.
- SettingsView gains a "Vocabulary Levels" section with five toggles; the
  existing "Levels" section is renamed "Verb Levels" for clarity.
- Due SRS cards always surface regardless of toggles. Disabling a level
  only stops new cards from that band entering the pool.

PracticeView gets "Nouns" and "Adjectives" rows under "Books".

DataLoader: new lexemeDataVersion gate that re-seeds the Lexeme table
from vocab_lexemes.json independent of book seeding. project.yml lists
the new JSON resource and the existing book_olly-vol2.json (which the
previous build was silently excluding because xcodegen rewrote the
project from project.yml).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Conjuga/Scripts/vocab/README.md

@@ -0,0 +1,62 @@
+# Vocab catalog build
+
+`build_lexemes.py` produces `Conjuga/vocab_lexemes.json`, the bundled catalog
+of frequency-ranked Spanish nouns and adjectives that powers the Noun /
+Adjective flashcard study modes.
+
+## Run
+
+```sh
+python3 build_lexemes.py
+```
+
+Downloads `frequency.csv` + `es-en.data` from a pinned commit of
+[`doozan/spanish_data`](https://github.com/doozan/spanish_data), caches them
+under `.cache/<commit>/`, joins them, and writes the JSON. Re-running is
+fast — only the join step happens after the first download.
+
+Override defaults:
+
+```sh
+python3 build_lexemes.py --max-nouns 3000 --max-adjectives 1000
+python3 build_lexemes.py --output /tmp/vocab.json
+```
+
+## Data sources & attribution
+
+All datasets are CC-licensed; the bundled catalog inherits CC-BY-SA. Credit
+in the app's About screen must read:
+
+> Vocabulary data: Wiktionary (CC-BY-SA), OpenSubtitles via FrequencyWords
+> (CC-BY-SA 3.0).
+
+- **`frequency.csv`** — derived from
+  [hermitdave/FrequencyWords](https://github.com/hermitdave/FrequencyWords)
+  (OpenSubtitles corpus), packaged by doozan. License: CC-BY-SA 3.0.
+- **`es-en.data`** — Spanish→English Wiktionary export in the
+  [`enwiktionary_wordlist`](https://github.com/doozan/enwiktionary_wordlist)
+  format. License: CC-BY-SA.
+
+The pinned doozan commit is at the top of `build_lexemes.py`
+(`DOOZAN_COMMIT`). Bump it to refresh; the cache key includes the commit so
+old data is auto-replaced.
+
+## Output shape
+
+```json
+[
+  {
+    "baseForm": "casa",
+    "english": "house",
+    "partOfSpeech": "noun",
+    "gender": "f",
+    "frequencyRank": 142,
+    "exampleES": "La casa es grande",
+    "exampleEN": "The house is big"
+  },
+  ...
+]
+```
+
+Sorted by `frequencyRank` ascending so the fresh-card path in `LexemePool`
+surfaces the most useful words first.