feat: [50 MRG] Spanish language pack — rubric, DELE bands, 4 samples, 4 tests (Closes #22)

[laurentketterle-hub]

Closes #22

Expands Spanish (ES) language pack with rubric, DELE framework bands, samples, and tests.

Changes

• Rubric: data/rubrics/es.json — Spanish skill descriptors (vocabulary, grammar, reading, writing, listening, speaking) with DELE mapping
• Framework bands: src/nokaman/models/toy.py — Added _dele_band() function, integrated into _framework_bands() for es language
• Samples (4 new):
  • es_writing_a2.json — Weekend narrative, past tense
  • es_writing_b1.json — Formal email requesting course info
  • es_writing_b2.json — Opinion essay on online language learning
  • es_speaking_a2.json — Spoken monologue with discourse markers
• Tests: tests/test_es_framework_bands.py — 4 tests covering DELE band presence, demo output, CEFR correlation, and sample loading

Verification

uv pip install -e ".[dev]" && python -m pytest tests/test_es_framework_bands.py tests/test_framework_bands.py -v
# 8 passed
python -m pytest tests/ -v
# 70 passed, 0 failed

[laurentketterle-hub]

/attempt 22

[laurentketterle-hub]

Friendly ping 👋 — this PR has been open for 3 days. Is there anything needed for review? Thanks!

[laurentketterle-hub]

/claim