Restore the missing diacritics in the Portuguese locale

[nank1ro]

122 --description-- sections in pt/ were written with the accents dropped:

Um indice de lista se comporta como qualquer outro nome de variavel
O comprimento de um array e o numero de itens que ele contem

They are real Portuguese, not untranslated English, and the rest of pt is correctly accented — so this is a minority defect that spread across 27 folders in all six programming languages. Found by flagging description prose (code fences and inline spans removed) of 120+ characters containing no diacritic at all.

This is what the earlier pt/javascript/conditionalStatements and pt/python/conditionalStatements note in #324 was pointing at; this PR is the general case.

What changed

The missing accents, and nothing else. No rewording, no reordering, no punctuation.

The interesting part is the e / é distinction — e is the conjunction "and", é is "is", and they are not interchangeable. Each standalone e had to be classified by meaning rather than replaced mechanically; same for a/à, esta/está, so/só, ate/até.

Diff shape

• 119 exercise files, 335 insertions / 335 deletions — line-for-line replacement. Three of the 122 turned out to need no change.
• 24 _theory.md files, +335 / −335 — mirrors the exercise delta exactly.
• curriculum.json unchanged.

Checks

• Round-trip proof: stripping every combining mark from the new text (and mapping ç→c) reproduces the old text character-for-character, 122 of 122. That is the evidence that only accents were touched and no prose was quietly rewritten.
• Detector re-run: 0 remaining.
• validator: +275436: All tests passed!