i18n: harmonize terminology and register across all locales

[mahlernim]

Full review pass over all eight translated string files, fixing content errors and settling the terminology and formality choices that had drifted apart.

Content errors

Locale	Problem
zh-rTW	export_help_message told users to look for a file named 「時間軸.json」. The literal filename Timeline.json had been translated, so the instructions pointed at a file that does not exist. Same string also gave the wrong iPhone menu path (位置和隱私權 instead of 個人內容).
fr	export_help_message had a stray character: OSur iPhone.
fr	privacy_summary and map_privacy_message said the file is never téléchargé, which reads as "downloaded". The claim is about upload. Now envoyé.
pt-BR	Same bug: "nunca é carregado" (upload) sat next to "Antes de carregar" (load). One word, two opposite meanings, adjacent strings.
de, fr, pt-BR	default_title used the wrong gender for Timeline ("Mein Timeline", "Mon Timeline", "Meu Timeline"); de default_title_template still carried the English possessive {name}\'s Timeline.
de	Mistranslations: share = Aktie (stock certificate), cancel = Stornieren (cancel an order), plus "Laden Timeline", "Abschlussvideo" and a broken CARTO sentence.

Formality register

German mixed 68 formal Sie strings against 29 informal du strings, the split falling roughly along old UI versus the newer journal and onboarding copy. Now uniformly du, matching Google's own German UI convention and the app's personal tone.

Spanish had the same split in reverse (13 usted against 67 tú, including timeline_setup_summary which switched register mid-sentence). Now uniformly tú.

"Timeline" terminology

Every locale mixed the Latin word with a localized equivalent for the same Google Maps feature. Each locale now uses one term, picked by majority:

Locale	Before	Now
de	Timeline 50 / Zeitachse, Zeitleiste, Chronik 19	Timeline
es	Timeline 58 / cronología, línea de tiempo 13	Timeline
fr	Timeline 60 / chronologie 10	Timeline
ja	タイムライン 59 / Timeline 4	タイムライン
ko	타임라인 59 / Timeline 9	타임라인
pt-BR	Linha do tempo 39 / Timeline 31	Linha do tempo
zh-rCN	时间轴 40 / 时间线, Timeline 16	时间轴
zh-rTW	時間軸 66 / Timeline 1	時間軸

Timeline.json and Timeline Visualizer stay literal everywhere. pt-BR was the worst case and also flipped Timeline's grammatical gender between strings; feminine a Linha do tempo throughout resolves both problems at once.

Other single-locale splits

Each collapsed to one term: de Rückblick vs Zusammenfassung, de Reise vs Ausflug, ja 要約 vs まとめ, pt Recapitulação vs Resumo vs Retrospectiva, es four renderings of "preset" (now preajuste, which also stops colliding with Ajustes = Settings), ko 프리셋 vs 사전 설정, zh-rTW 預設組合 vs 預設, zh-rCN/rTW 行程 vs 旅行 for "trip".

Typography

es and zh-rCN used ... where every other locale uses …. zh-rCN was missing spaces around Latin text and had stray spaces after full-width punctuation. Three leftover "Google Maps" in zh-rCN/rTW became Google 地图 / 地圖.

Verification

• python -m pytest tests/ -q — 89 passed
• All eight locale files parse as XML, key parity with the source set is unchanged, and every %n$s placeholder set matches its English original
• No unescaped apostrophes, literal newlines, or invalid escape sequences introduced

Not addressed

French uses bare carnet as shorthand for carnet de voyage in about 25 strings. It is consistent in kind and reads naturally, so it was treated as style rather than error.

app/src/journalLab/res/values/strings.xml duplicates 13 strings byte-for-byte from main. Because the flavor overrides main, translations drift silently, and the de and es copies had already gone stale during this pass (resynced here by hand). Removing that duplication is worth a separate change.