fix: route Spanish targets to Spanish CBT scaffolding, not French

[TrainTravel]

Summary

Fixes a latent routing bug preserved through the language-* consolidation in PR #36: Spanish learners were getting French Cognitive Behavioral Therapy prompts because targetLang === 'es' fell into the French branch of language-chat's cbtBlock and granularityBlock.

A Spanish journal entry could trigger:

Quand ça s'est passé, quelle a été ta première pensée ?

instead of the correct Spanish phrasing. That's an obvious quality bug for the emotional-granularity goal — coaching prompts have to be in the target language to function as language practice.

What changed

supabase/functions/language-chat/index.ts:

• granularityBlock — added a Spanish branch with Spanish vague-emotion examples:

  • mal → agotado, desanimado, abrumado
  • estresado → ansioso, desbordado, tenso
  • bien → sereno, agradecido, aliviado
  • triste → melancólico, nostálgico, decepcionado
  • contento → encantado, aliviado, entusiasmado
  • cansado → exhausto, agotado, vacío

• cbtBlock — added a Spanish branch with all 6 CBT techniques translated:

  1. Thought Records: "¿Cuál fue tu primer pensamiento cuando eso pasó?"
  2. Cognitive Distortions: "Noto un patrón interesante aquí…" / "¿hay otra forma de verlo?"
  3. Behavioral Experiments: "¿Y si lo intentaras…?"
  4. Downward Arrow: "Si fuera cierto, ¿qué significaría para ti?"
  5. Evidence Gathering: "¿Qué evidencia tienes a favor de ese pensamiento? ¿Y en contra?"
  6. Values Alignment: "¿Por qué es importante esto para ti?"

• Added explicit "use tú (informal), not usted" instruction — neutral Latin-American Spanish, appropriate register for a personal journaling/coaching context.

French CBT stays as the explicit default fallback. Zero behavior change for any other language (fr, zh-Hans, zh-Hant, ja).

Test plan

• npx tsc --noEmit — clean
• npx vitest run — 188 passed / 189 (only pre-existing useJournal startFreeWrite)
• Edge function code only — no React unit tests apply. Manual verification recommended after deployment.
• Manual after merge: set target=Spanish, post a Spanish journal entry, verify the chat response uses Spanish CBT phrasing, not French.

Native review caveat

My Spanish is decent (better than my Japanese) but not native. The translations follow neutral Latin-American conventions. A native speaker pass via iTalki or r/translator is still worthwhile before high-volume Spanish users hit the app — same recommendation as the Japanese prompts. The same copy-paste critique template applies.

Out of scope

• Spanish chrome translations for t() / bilingual() call sites (separate translation-pass PR)
• Adjusting the en/es vague-word list in language-feedback (English keys are still hardcoded there; lower priority since the language NAME in the prompt is correctly interpolated)

🤖 Generated with Claude Code